0000314489-26-000033 | 10-Q | XBRL Viewer

PORTFOLIO LOANS

3 Months Ended

Mar. 31, 2026

Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]

NOTE 4. PORTFOLIO LOANS

Loan Categories

Busey’s lending can be summarized in two primary categories: commercial and retail. Loans within these categories are further classified by lending activity: C&I and other commercial, commercial real estate, real estate construction, retail real estate, and retail other. Distributions of the loan portfolio by loan category and lending activity is presented in the following table:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Commercial loans
C&I and other commercial	$	4,124,737	$	4,229,208
CRE	5,566,044		5,550,018
Real estate construction	1,052,505		1,039,289
Total commercial loans	10,743,286		10,818,515
Retail loans
Retail real estate	2,119,621		2,154,616
Retail other	596,983		594,668
Total retail loans	2,716,604		2,749,284

Total portfolio loans	13,459,890		13,567,799
ACL	(169,054)		(174,023)
Portfolio loans, net	$	13,290,836	$	13,393,776

Net deferred loan origination costs included in the balances above were $5.7 million as of March 31, 2026, compared to $7.0 million as of December 31, 2025. Net accretable purchase accounting adjustments included in the balances above reduced loans by $81.0 million as of March 31, 2026, and $86.6 million as of December 31, 2025. Deposit account overdrafts reported as loans totaled $6.1 million as of March 31, 2026, and $7.1 million as of December 31, 2025.

Busey did not execute any significant loan purchases or sales during the three months ended March 31, 2026. Other than loans assumed through acquisition activities, Busey did not execute any significant loan purchases or sales during the three months ended March 31, 2025.

Pledged Loans

Busey has executed a blanket lien with the FHLB. The principal balance of loans Busey has pledged as collateral with the FHLB and Federal Reserve Bank for liquidity, which Busey is able to borrow against, is set forth in the table below:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Pledged loans
FHLB	$	7,199,169	$	5,051,512
Federal Reserve Bank	1,923,484		1,854,423
Total pledged loans	$	9,122,653	$	6,905,935

Risk Grading

Busey utilizes a loan grading scale to assign a risk grade to all of its loans. A description of the general characteristics of each grade is as follows:

•Pass – This category includes loans that are all considered acceptable credits, ranging from investment or near investment grade, to loans made to borrowers who exhibit credit fundamentals that meet or exceed industry standards.

•Watch – This category includes loans that warrant a higher-than-average level of monitoring to ensure that weaknesses do not cause the inability of the credit to perform as expected. These loans are not necessarily a problem due to other inherent strengths of the credit, such as guarantor strength, but have above average concern and monitoring.

•Special mention – This category is for “Other Assets Specially Mentioned” loans that have potential weaknesses, which may, if not checked or corrected, weaken the asset or inadequately protect Busey’s credit position at some future date.

•Substandard – This category includes “Substandard” loans, determined in accordance with regulatory guidelines, for which the accrual of interest has not been stopped. Assets so classified must have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that Busey will sustain some loss if the deficiencies are not corrected.

•Substandard non-accrual – This category includes loans that have all the characteristics of a “Substandard” loan with additional factors that make collection in full highly questionable and improbable. Such loans are placed on non-accrual status and may be dependent on collateral with a value that is difficult to determine.

All loans are graded at their inception. Commercial lending relationships that are $2.0 million or less are usually processed through an expedited underwriting process. Most commercial loans greater than $2.0 million are included in a portfolio review at least annually. Commercial loans greater than $0.35 million that have a grading of special mention or worse are typically reviewed on a quarterly basis. Interim reviews may take place if circumstances of the borrower warrant a more frequent review.

Risk grades of portfolio loans and gross charge-offs are presented in the tables below by lending activity, further sorted by origination year:


	As of and For The Three Months Ended March 31, 2026
Risk Grade Ratings	Term Loans Amortized Cost Basis by Origination Year												Revolving Loans		Total
(dollars in thousands)	2026		2025		2024		2023		2022		Prior
C&I and other commercial
Pass	$	176,684	$	703,182	$	444,948	$	281,266	$	190,104	$	247,451	$	1,356,182	$	3,399,817
Watch	5,980		37,677		79,414		54,522		30,451		48,220		164,690		420,954
Special Mention	6,657		18,453		12,256		19,335		21,324		6,427		61,112		145,564
Substandard	14,231		4,942		4,800		45,663		20,228		9,753		27,108		126,725
Substandard non-accrual	3		4,384		3,318		1,183		4,362		5,442		12,985		31,677
Total C&I and other commercial	203,555		768,638		544,736		401,969		266,469		317,293		1,622,077		4,124,737
Gross charge-offs	$	50	$	104	$	—	$	257	$	6,180	$	743	$	171	$	7,505

CRE
Pass	374,592		970,541		445,815		660,590		934,154		1,183,257		45,082		4,614,031
Watch	100,410		131,248		55,151		126,753		139,092		193,822		2,794		749,270
Special Mention	19,919		54,289		5,388		27,987		16,485		44,198		731		168,997
Substandard	1,234		2,122		421		3,243		3,860		12,184		215		23,279
Substandard non-accrual	—		519		253		5,366		483		3,846		—		10,467
Total CRE	496,155		1,158,719		507,028		823,939		1,094,074		1,437,307		48,822		5,566,044
Gross charge-offs	—		—		—		—		—		—		—		—

Real estate construction
Pass	102,064		373,586		251,234		69,954		69,315		7,516		74,606		948,275
Watch	13,896		2,153		—		1,978		42,561		160		6,198		66,946
Special Mention	—		18,945		—		—		—		6,434		—		25,379
Substandard	—		10,876		—		—		—		756		—		11,632
Substandard non-accrual	—		—		273		—		—		—		—		273
Total real estate construction	115,960		405,560		251,507		71,932		111,876		14,866		80,804		1,052,505
Gross charge-offs	—		—		—		—		—		—		—		—

Retail real estate
Pass	45,952		138,678		120,634		252,430		436,101		836,870		246,306		2,076,971
Watch	86		2,590		530		24,972		1,464		512		545		30,699
Special Mention	—		47		72		—		1,432		1,661		207		3,419
Substandard	—		—		—		4,108		135		1,100		—		5,343
Substandard non-accrual	—		357		308		127		579		1,058		760		3,189
Total retail real estate	46,038		141,672		121,544		281,637		439,711		841,201		247,818		2,119,621
Gross charge-offs	70		—		—		—		—		—		81		151

Retail other
Pass	750		4,850		1,889		29,179		26,892		5,245		527,985		596,790



Substandard non-accrual	—		—		—		76		116		—		1		193
Total retail other	750		4,850		1,889		29,255		27,008		5,245		527,986		596,983
Gross charge-offs	172		—		—		10		—		—		2		184

Total portfolio loans	$	862,458	$	2,479,439	$	1,426,704	$	1,608,732	$	1,939,138	$	2,615,912	$	2,527,507	$	13,459,890
Total gross charge-offs	$	292	$	104	$	—	$	267	$	6,180	$	743	$	254	$	7,840


	As of and For The Year Ended December 31, 2025
Risk Grade Ratings	Term Loans Amortized Cost Basis by Origination Year												Revolving Loans		Total
(dollars in thousands)	2025		2024		2023		2022		2021		Prior
C&I and other commercial
Pass	$	833,539	$	486,278	$	342,560	$	207,053	$	178,429	$	122,904	$	1,396,826	$	3,567,589
Watch	21,750		79,853		56,387		38,786		48,624		16,778		112,935		375,113
Special Mention	21,712		11,609		56,578		26,343		5,339		800		54,433		176,814
Substandard	8,336		605		20,444		14,603		9,868		3,655		17,883		75,394
Substandard non-accrual	1,489		3,899		600		10,265		948		4,560		12,537		34,298
Total C&I and other commercial	886,826		582,244		476,569		297,050		243,208		148,697		1,594,614		4,229,208
Gross charge-offs	$	4,667	$	3,332	$	4,347	$	1,450	$	13,591	$	11,456	$	5,716	$	44,559

CRE
Pass	1,077,169		483,950		710,448		1,035,426		740,680		515,631		43,830		4,607,134
Watch	210,673		61,926		119,986		143,072		161,387		69,789		2,572		769,405
Special Mention	49,648		22,642		2,991		13,811		32,109		18,858		908		140,967
Substandard	2,416		679		3,857		4,873		7,316		5,324		215		24,680
Substandard non-accrual	72		—		4,547		—		—		3,213		—		7,832
Total CRE	1,339,978		569,197		841,829		1,197,182		941,492		612,815		47,525		5,550,018
Gross charge-offs	1,297		11,057		—		—		253		—		—		12,607

Real estate construction
Pass	395,019		268,117		107,930		89,673		5,356		2,733		74,237		943,065
Watch	18,571		2,112		3,999		22,561		167		—		7,221		54,631
Special Mention	17,961		—		—		—		6,573		—		—		24,534
Substandard	16,020		—		—		—		766		—		—		16,786
Substandard non-accrual	—		273		—		—		—		—		—		273
Total real estate construction	447,571		270,502		111,929		112,234		12,862		2,733		81,458		1,039,289
Gross charge-offs	—		—		—		—		—		—		—		—

Retail real estate
Pass	93,212		127,475		269,877		446,309		407,851		508,504		252,987		2,106,215
Watch	2,686		569		24,601		1,492		267		482		577		30,674
Special Mention	47		78		4,028		1,454		1,686		—		214		7,507
Substandard	—		—		108		440		484		631		136		1,799
Substandard non-accrual	154		308		128		523		264		2,841		4,203		8,421
Total retail real estate	96,099		128,430		298,742		450,218		410,552		512,458		258,117		2,154,616
Gross charge-offs	1,164		—		—		—		—		51		36		1,251

Retail other
Pass	5,233		2,265		33,349		30,321		4,561		885		517,680		594,294



Substandard non-accrual	—		—		76		134		—		—		164		374
Total retail other	5,233		2,265		33,425		30,455		4,561		885		517,844		594,668
Gross charge-offs	546		147		270		47		—		74		141		1,225

Total portfolio loans	$	2,775,707	$	1,552,638	$	1,762,494	$	2,087,139	$	1,612,675	$	1,277,588	$	2,499,558	$	13,567,799
Total gross charge-offs	$	7,674	$	14,536	$	4,617	$	1,497	$	13,844	$	11,581	$	5,893	$	59,642

Past Due and Non-accrual Loans

An analysis of portfolio loans that were past due and still accruing, or on a non-accrual status, is presented in the table below:


	As of March 31, 2026
	Loans Past Due, Still Accruing						Non-Accrual Loans		Non-Accrual Loans with No Allowance for Credit Losses
(dollars in thousands)	30-59 Days		60-89 Days		90+Days
Commercial loans
C&I and other commercial	$	2,828	$	412	$	518	$	31,677	$	7,451
CRE	2,195		—		—		10,467		3,726
Real estate construction	348		—		—		273		158
Past due and non-accrual commercial loans	5,371		412		518		42,417		11,335
Retail loans
Retail real estate	3,093		4,269		—		3,189		349
Retail other	4,290		30		294		193		—
Past due and non-accrual retail loans	7,383		4,299		294		3,382		349
Total past due and non-accrual loans	$	12,754	$	4,711	$	812	$	45,799	$	11,684


	As of December 31, 2025
	Loans Past Due, Still Accruing						Non-Accrual Loans		Non-Accrual Loans with No Allowance for Credit Losses
(dollars in thousands)	30-59 Days		60-89 Days		90+Days
Commercial loans
C&I and other commercial	$	3,577	$	593	$	2,128	$	34,298	$	4,612
CRE	484		2,514		—		7,832		1,588
Real estate construction	—		—		—		273		158
Past due and non-accrual commercial loans	4,061		3,107		2,128		42,403		6,358
Retail loans
Retail real estate	2,457		4,280		136		8,421		349
Retail other	2,491		79		24		374		—
Past due and non-accrual retail loans	4,948		4,359		160		8,795		349
Total past due and non-accrual loans	$	9,009	$	7,466	$	2,288	$	51,198	$	6,707

Gross interest income recorded on 90+ days past due loans, and that would have been recorded on non-accrual loans if they had been accruing interest in accordance with their original terms, was $1.1 million for the three months ended March 31, 2026, and was $0.2 million for the three months ended March 31, 2025. The amount of interest collected on those loans and recognized on a cash basis that was included in interest income was $0.6 million for the three months ended March 31, 2026, and was immaterial for the three months ended March 31, 2025.

Loan Modifications for Borrowers Experiencing Financial Difficulty

The following tables present the amortized cost basis of loans that were modified—specifically in the form of (1) principal forgiveness, (2) an interest rate reduction, (3) an other-than-insignificant payment deferral, and/or (4) a term extension—for borrowers experiencing financial difficulty during the periods indicated, disaggregated by lending activity and the type of modification:


	Three Months Ended March 31, 2026
(dollars in thousands)	Payment Deferral		Term Extension		% of Total Class of Financing Receivable
Modified Loans
C&I and other commercial	$	2,215	$	34,349	0.9	%




Total loans modified during the period1	$	2,215	$	34,349	0.3	%

___________________________________________

1.Modifications were primarily for loans classified as substandard.


	Three Months Ended March 31, 2025
(dollars in thousands)	Payment Deferral		Term Extension		% of Total Class of Financing Receivable
Modified Loans
C&I and other commercial	$	10,832	$	21,923	0.7	%
CRE	—		4,719		0.1	%
Real estate construction	—		5,208		0.5	%


Total loans modified during the period1	$	10,832	$	31,850	0.3	%

___________________________________________

1.All modifications were for loans classified as substandard.

The following table provides, as applicable for loan modifications made during the periods indicated for borrowers experiencing financial difficulty, the weighted average interest rate reductions and weighted average term extensions:

Three Months Ended March 31,

2026

2025

Weighted Average Term Extension

C&I and other commercial

10 months

1.9 years

CRE

—

6 months

Real estate construction

—

1.3 years

Aggregate effect

10 months

1.6 years

Payment deferrals for borrowers experiencing financial difficulty can include deferrals of 3 or more payments to the end of the loan, accommodations to restructure the payment terms of the loan, or accommodations to allow for an interest-only period on the loan.

Performance of Modified Loans

Busey closely monitors the performance of the loans that are modified for borrowers experiencing financial difficulty to understand the effectiveness of its modification efforts. The following table depicts the payment performance of loans modified during the last twelve months:


	As of March 31, 2026
(dollars in thousands)	Current		30-89 Days		90+ Days		Non-accrual
Modified Loans
C&I and other commercial	$	42,179	$	—	$	—	$	4,476
CRE	1,833		—		—		273
Real estate construction	10,876		—		—		—


Loans modified during the last twelve months	$	54,888	$	—	$	—	$	4,749

Busey had commitments of $15.1 million as of March 31, 2026, and $13.5 million as of December 31, 2025, to lend additional funds to debtors experiencing financial difficulty for whom Busey modified a loan within the past twelve months.

A default occurs when a loan is 90 days or more past due or transferred to non-accrual status. The following table presents loans that defaulted after having been modified during the twelve months before the default.


	Three Months Ended March 31, 2026

(dollars in thousands)		Term Extension
Loans with Subsequent Defaults

CRE		$	273



Modified loans with subsequent defaults		$	273

No loans had a default during the three months ended March 31, 2025, after having been modified during the twelve months before that default for borrowers experiencing financial difficulty.

Collateral Dependent Loans

Management's evaluation as to the ultimate collectability of loans includes estimates regarding future cash flows from operations and the value of property, real and personal, pledged as collateral. These estimates are affected by changing economic conditions and the economic prospects of borrowers. Collateral dependent loans are loans in which repayment is expected to be provided solely by the operation or sale of the underlying collateral and there are no other available and reliable sources of repayment. Collateral dependent loans are secured by (1) business assets, for C&I and other commercial loans; (2) real estate, for CRE and retail real estate loans; and (3) vehicles and other personal assets, for retail other loans. Loans are written down to the lower of cost or fair value of the underlying collateral, less estimated costs to sell. Busey had $41.8 million and $47.8 million of collateral dependent loans as of March 31, 2026, and December 31, 2025, respectively.

OREO and Other Repossessed Assets

Busey held $0.1 million of commercial OREO, an immaterial amount of residential OREO, and $3.2 million of other repossessed assets, as of March 31, 2026. Busey’s recorded investment in residential real estate loans that were in the process of foreclosure was $1.2 million as of March 31, 2026. Busey follows Federal Housing Finance Agency guidelines on single-family foreclosures and real estate owned evictions on portfolio loans.

Allowance for Credit Losses

The ACL is a valuation account that is deducted from the portfolio loans’ amortized cost bases to present the net amount expected to be collected on the portfolio loans. The ACL is established through the provision for credit losses charged to income. Portfolio loans are charged off against the ACL when management believes the uncollectibility of a loan balance is confirmed. Recoveries are recognized up to the aggregate amount of previously charged-off balances.

Management estimates the ACL balance using relevant available information from internal and external sources relating to past events, current conditions, and reasonable and supportable forecasts. Historical credit loss experience provides the basis for the estimation of expected credit losses. The ACL consists of three components: (1) specific allocations/individual reserves; (2) quantitative reserves; and (3) qualitative reserves.

•Specific allocations/individual reserves – When a loan no longer exhibits risk characteristics that are similar to other loans, that loan is individually evaluated. Individual reserves are calculated for loans that are on a non-accrual status that are greater than a defined dollar threshold or loans that have disparate risk characteristics. Reserves may be based on collateral, for collateral-dependent loans, or on quantitative and qualitative factors, including expected cash flow, market sentiment, and guarantor support.

•Quantitative reserves – Busey implemented a new non-discounted cash flow model in the second quarter of 2025 that used combined historical loan data from Busey Bank beginning in 2004 and CrossFirst Bank since its inception in 2007. The model incorporates various baseline forecast scenarios and national unemployment rates with either national gross domestic product, the national home price index, or the national commercial real estate price index. Further, prepayment and curtailment expectations are factored into the model. Due to the continued economic uncertainty in the markets in which the Company operates, Busey will continue to utilize a forecast period of 12 months with an immediate reversion to historical loss rates beyond this forecast period in its ACL estimate.

•Qualitative reserves – Busey uses qualitative factors to adjust the historical loss factors for current and forecasted conditions. Busey considers the ten qualitative factors identified in the Interagency Guidance and ASC Topic 326 at each reporting date.

The following tables summarize activity in the ACL attributable to each lending activity. Allocation of a portion of the ACL to one lending activity does not preclude its availability to absorb losses from other lending activities:


	Three Months Ended March 31, 2026
(dollars in thousands)	C&I and Other Commercial		CRE		Real Estate Construction		Retail Real Estate		Retail Other		Total
ACL balance, December 31, 2025	$	61,370	$	70,328	$	11,568	$	29,178	$	1,579	$	174,023


Provision for loan losses	3,556		(234)		1,019		(1,944)		(4)		2,393
Charged-off	(7,505)		—		—		(151)		(184)		(7,840)
Recoveries	383		6		1		57		31		478
ACL balance, March 31, 2026	$	57,804	$	70,100	$	12,588	$	27,140	$	1,422	$	169,054


	Three Months Ended March 31, 2025
(dollars in thousands)	C&I and Other Commercial		CRE		Real Estate Construction		Retail Real Estate		Retail Other		Total
ACL balance, December 31, 2024	$	21,589	$	32,301	$	3,345	$	23,711	$	2,458	$	83,404
Day 1 PCD1	75,569		21,588		2,112		1,430		84		100,783
Day 2 Provision for loan losses2	22,648		15,104		2,911		1,628		142		42,433
Provision for loan losses	623		(393)		311		(503)		(19)		19
Charged-off3	(31,221)		(253)		—		—		(361)		(31,835)
Recoveries	96		131		10		133		36		406
ACL balance, March 31, 2025	$	89,304	$	68,478	$	8,689	$	26,399	$	2,340	$	195,210

___________________________________________

1.The Day 1 PCD was attributable to the CrossFirst acquisition (see “Note 2. Business Combinations”), and represents the initial adjustment to the fair value of the PCD loans.

2.The Day 2 provision for loan losses was attributable to the CrossFirst acquisition (see “Note 2. Business Combinations”), and represents the initial provision for non-PCD loans.

3.Charged-off amounts included $29.6 million for PCD loans assumed in the CrossFirst acquisition, which were fully reserved at acquisition and did not require recording additional provision expense.

EARNINGS PER COMMON SHARE

3 Months Ended

Mar. 31, 2026

Earnings Per Share [Abstract]

EARNINGS PER COMMON SHARE

NOTE 14. EARNINGS PER COMMON SHARE

Basic earnings per common share is computed by dividing net income available to common stockholders by the weighted average number of common shares outstanding, which include DSUs that are vested but not delivered. Net income available to common stockholders is net income less dividends that have been declared on Busey’s preferred stock (all of which is non-cumulative). Diluted earnings per common share is computed using the treasury stock method and reflects the potential dilution that could occur if shares were issued for Busey’s outstanding equity-based awards.

Earnings per common share have been computed as follows:


	Three Months Ended March 31,
(dollars in thousands, except per share amounts)		2026		20251
Net income (loss)		$	49,981	$	(29,990)
Dividends on preferred stock		(4,589)		—
Net income (loss) available to common stockholders		$	45,392	$	(29,990)

Weighted average number of common shares outstanding, basic		86,692,001		68,517,647








Dilutive effect of outstanding equity-based awards		1,139,294		—
Weighted average number of common shares outstanding, diluted		87,831,295		68,517,647

Basic earnings (loss) per common share		$	0.52	$	(0.44)
Diluted earnings (loss) per common share		$	0.52	$	(0.44)

Anti-dilutive equity-based awards		—		2,794,422

___________________________________________

1.Since the Company experienced a net loss for the three months ended March 31, 2025, the inclusion of all potential common shares outstanding would have been anti-dilutive, so diluted loss per common share was the same as basic loss per common share.

OPERATING SEGMENTS AND RELATED INFORMATION (Tables)

3 Months Ended

Mar. 31, 2026

Segment Reporting [Abstract]

Schedule of Information Relating to Operating Segments

Goodwill and total assets are summarized below by operating segment. The “other” category included in the tables below consists of the parent company and the elimination of intercompany transactions:


	As of March 31, 2026
(dollars in thousands)	Banking		Wealth Management		FirsTech		Other		Total
Goodwill	$	359,263	$	14,108	$	8,992	$	—	$	382,363
Total assets	17,835,924		155,714		44,964		20		18,036,622


	As of December 31, 2025
(dollars in thousands)	Banking		Wealth Management		FirsTech		Other		Total
Goodwill	$	360,180	$	14,108	$	8,992	$	—	$	383,280
Total assets	17,880,797		152,422		45,373		26,144		18,104,736

Financial results by operating segment, including significant expense categories provided to the chief operating decision maker, are summarized below:


	Three Months Ended March 31, 2026
(dollars in thousands)	Banking		Wealth Management		FirsTech		Other		Total
Interest income	$	225,407	$	—	$	—	$	78	$	225,485
Intersegment interest income	—		—		15		(15)		—
Interest expense	68,874		—		—		2,642		71,516
Intersegment interest expense	504		—		—		(504)		—
Net interest income	156,029		—		15		(2,075)		153,969
Provision for credit losses	3,058		—		—		—		3,058
Net interest income after provision for credit losses	152,971		—		15		(2,075)		150,911

Noninterest income
Wealth management fees	—		19,370		—		—		19,370
Payment technology solutions	—		—		5,077		—		5,077
Treasury management services	4,826		—		—		—		4,826
Card services and ATM fees	4,646		—		—		—		4,646
Other service charges on deposit accounts	1,506		—		—		—		1,506
All other noninterest income	7,621		157		—		(938)		6,840
Intersegment noninterest income	2,833		—		561		(3,394)		—
Noninterest income	21,432		19,527		5,638		(4,332)		42,265

Revenue	177,461		19,527		5,653		(6,407)		196,234

Noninterest expense
Salaries, wages, and employee benefits	71,707		8,866		4,657		—		85,230
Data processing	8,182		763		886		33		9,864
Amortization of intangible assets	4,110		181		—		—		4,291
Interchange expense	—		—		1,116		—		1,116
All other noninterest expense	25,682		852		676		1,808		29,018
Intersegment noninterest expense	679		750		540		(1,969)		—
Noninterest expense	110,360		11,412		7,875		(128)		129,519

Income (loss) before income taxes	64,043		8,115		(2,222)		(6,279)		63,657
Income taxes	13,803		1,948		(542)		(1,533)		13,676
Net income (loss)	$	50,240	$	6,167	$	(1,680)	$	(4,746)	$	49,981


	Three Months Ended March 31, 2025
(dollars in thousands)	Banking		Wealth Management		FirsTech		Other		Total
Interest income	$	166,812	$	—	$	—	$	3	$	166,815
Intersegment interest income	—		—		13		(13)		—
Interest expense	58,517		—		—		4,567		63,084
Intersegment interest expense	491		—		—		(491)		—
Net interest income	107,804		—		13		(4,086)		103,731
Provision for credit losses	45,593		—		—		—		45,593
Net interest income after provision for credit losses	62,211		—		13		(4,086)		58,138

Noninterest income
Wealth management fees	—		17,364		—		—		17,364
Payment technology solutions	—		—		5,073		—		5,073
Treasury management services	3,017		—		—		—		3,017
Card services and ATM fees	3,709		—		—		—		3,709
Other service charges on deposit accounts	1,533		—		—		—		1,533
All other noninterest income	(9,379)		202		(2)		(294)		(9,473)
Intersegment noninterest income	352		—		345		(697)		—
Noninterest income	(768)		17,566		5,416		(991)		21,223

Revenue	107,036		17,566		5,429		(5,077)		124,954

Noninterest expense
Salaries, wages, and employee benefits	46,726		7,031		2,481		11,325		67,563
Data processing	7,949		593		937		96		9,575
Amortization of intangible assets	2,841		242		—		—		3,083
Interchange expense	—		—		1,343		—		1,343
All other noninterest expense	19,825		737		617		9,287		30,466
Intersegment noninterest expense	4,665		780		369		(5,814)		—
Noninterest expense	82,006		9,383		5,747		14,894		112,030

Income (loss) before income taxes	(20,563)		8,183		(318)		(19,971)		(32,669)
Income taxes	(870)		1,964		(79)		(3,694)		(2,679)
Net income (loss)	$	(19,693)	$	6,219	$	(239)	$	(16,277)	$	(29,990)

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 49,981	$ (29,990)
Unrealized/Unrecognized gains (losses) on debt securities:
Net unrealized holding gains (losses) on debt securities available for sale	(13,434)	23,827
Reclassification adjustment for realized (gains) losses on debt securities available for sale included in net income	(23)	15,537
Amortization of unrecognized losses on securities transferred to held to maturity	984	1,133
Tax effect	3,124	(12,414)
Net change in unrealized/unrecognized gains (losses) on debt securities	(9,349)	28,083
Unrealized gains (losses) on cash flow hedges:
Net unrealized holding gains (losses) on cash flow hedges	(3,712)	6,098
Reclassification adjustment for realized (gains) losses on cash flow hedges included in net income	1,403	2,060
Tax effect	578	(2,012)
Net change in unrealized gains (losses) on cash flow hedges	(1,731)	6,146
OCI	(11,080)	34,229
Total comprehensive income	$ 38,901	$ 4,239

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Cash flows provided by (used in) operating activities
Net income (loss)	$ 49,981	$ (29,990)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Provision for credit losses	3,058	45,593
Amortization of intangible assets	4,291	3,083
Amortization of mortgage servicing rights	203	168
Depreciation and amortization of premises and equipment	3,578	2,649
Net amortization (accretion) on portfolio loans	(5,626)	(1,164)
Net amortization (accretion) of premium (discount) on investment securities	(450)	1,437
Net amortization (accretion) of premium (discount) on time deposits	8	(659)
Net amortization (accretion) of premium (discount) on FHLB advances and other borrowings	462	433
Impairment of fixed assets held for sale	11	188
Impairment of mortgage servicing rights	(147)	(2)
Unrealized (gains) losses recognized on equity securities, net	963	231
(Gain) loss on sales of debt securities, net	(23)	15,537
(Gain) loss on sales of loans, net	(315)	(197)
(Gain) loss on sales of OREO and other repossessed assets	(15)	(16)
(Gain) loss on sales of premises and equipment	(85)	25
(Gain) loss on life insurance proceeds	0	(211)
Increase in cash surrender value of bank owned life insurance	(1,616)	(1,235)
Provision for deferred income taxes expense (benefit)	(4,728)	1,761
Stock-based compensation expense	4,136	3,394
Mortgage loans originated for sale	(18,887)	(13,169)
Proceeds from sales of mortgage loans	19,732	9,802
(Increase) decrease in other assets	8,272	(7,135)
Decrease in other liabilities	(11,268)	(22,141)
Net cash provided by operating activities	51,535	8,382
Cash flows provided by (used in) investing activities
Purchases of interest-bearing time deposits in other banks	(245)	(100)
Proceeds from maturities of interest-bearing time deposits in other banks	345	710
Purchases of equity securities	0	(742)
Proceeds from sales of equity securities	1	5,650
Purchases of debt securities available for sale	(140,488)	(336,428)
Proceeds from sales of debt securities available for sale	0	528,940
Proceeds from paydowns and maturities of debt securities available for sale	75,213	92,454
Proceeds from paydowns and maturities of debt securities held to maturity	21,401	11,754
Purchases of restricted bank stock	(8,757)	(10)
Proceeds from the redemption of restricted bank stock	4,041	3
Net (increase) decrease in loans	104,603	(93,249)
Net cash received in (paid for) acquisitions (see Note 2)	0	385,804
Cash paid for premiums on bank-owned life insurance	(42)	(46)
Proceeds from life insurance	0	3,306
Purchases of premises and equipment	(2,458)	(1,797)
Proceeds from disposition of premises and equipment	296	0
Net proceeds from OREO and other repossessed assets	1,303	14,576
Net cash provided by investing activities	55,213	610,825
Cash flows provided by (used in) financing activities
Net decrease in deposits	(169,906)	(94,060)
Net decrease in federal funds purchased and securities sold under agreements to repurchase	(10,565)	(18,270)
Proceeds from short-term borrowings	5,276,801	0
Repayment of short-term borrowings	(5,106,801)	0
Proceeds from other borrowings, net of debt issuance costs	11,000	16,667
Repayment of other borrowings	(45)	(30)
Cash dividends paid	(27,200)	(14,224)
Purchase of treasury stock	(66,149)	(4,836)
Cash paid for withholding taxes on stock-based payments	(6,486)	(910)
Issuance of treasury stock for the ESPP	838	619
Common stock issuance costs	0	(920)
Net cash used in financing activities	(98,513)	(115,964)
Net increase in cash and cash equivalents	8,235	503,243
Cash and cash equivalents, beginning of period	280,227	682,410
Cash and cash equivalents, ending of period	288,462	1,185,653
Cash payments for:
Interest	70,701	42,514
Non-cash investing and financing activities:
OREO and other repossessed assets acquired in settlement of loans	0	14,844
Transfer of loans held for sale to portfolio loans	$ 10	$ 0

OPERATING SEGMENTS AND RELATED INFORMATION

3 Months Ended

Mar. 31, 2026

Segment Reporting [Abstract]

OPERATING SEGMENTS AND RELATED INFORMATION

NOTE 16. OPERATING SEGMENTS AND RELATED INFORMATION

Busey’s reportable segments are determined by its chief executive officer, who is the designated chief operating decision maker. Busey is organized into three reportable operating segments: Banking, Wealth Management, and FirsTech. These operating segments are strategic business units that are separately managed, as they offer different products and services and have different marketing strategies.

Banking

The Banking operating segment provides a full range of banking services to individual and corporate customers through First Busey Corporation’s wholly-owned bank subsidiary, Busey Bank.

Busey Bank has 80 banking centers located throughout Illinois; the St. Louis, Missouri MSA; southwest Florida; Indianapolis, Indiana; the Dallas-Fort Worth MSA; the Kansas City MSA; Wichita, Kansas; Oklahoma City and Tulsa, Oklahoma; Phoenix and Tucson, Arizona; Denver and Colorado Springs, Colorado; and Clayton, New Mexico.

Banking services offered to individual customers include customary types of demand and savings deposits, money transfers, safe deposit services, individual retirement accounts and other fiduciary services, automated teller machines, and technology-based networks, as well as a variety of loan products including residential real estate, home equity lines of credit, and consumer loans. Banking services offered to corporate customers include commercial, CRE, real estate construction, and agricultural loans, as well as commercial depository services such as cash management.

Wealth Management

The Wealth Management operating segment provides a full range of asset management, investment, brokerage, fiduciary, philanthropic advisory, tax preparation, and farm management services to individuals, businesses, and foundations. Services are provided through Busey Capital Management, Inc., a wholly-owned subsidiary of Busey Bank, and Busey Wealth Management, a division of Busey Bank.

Wealth management services tailored to individuals include trust and estate advisory services and financial planning. Business services include business succession planning and employee retirement plan services. Services for foundations include investment strategy consulting and fiduciary services.

FirsTech

The FirsTech operating segment provides comprehensive and innovative payment technology solutions through Busey Bank’s wholly-owned subsidiary, FirsTech. FirsTech's multi-channel payment platform allows businesses to collect payments from their customers in a variety of ways to enable fast, frictionless payments. Payment method vehicles include text-based mobile bill pay; interactive voice response; electronic payment concentration delivered to Automated Clearing House networks, money management, and credit card networks; walk-in payment processing for customers at retail pay agents; customer service payments made over a telephone; direct debit services; merchant services referral solutions serving partner financial institutions and their business customers; and lockbox remittance processing for customers to make payments by mail. FirsTech also provides additional tools to help clients with billing, reconciliation, bill reminders, and treasury services.

FirsTech's client base represents a diverse set of industries, with a higher concentration in highly regulated industries, such as financial institutions, utility, insurance, and telecommunications industries.

Segment Financial Information

The segment financial information provided below has been derived from information used by management to monitor and manage Busey’s financial performance. The accounting policies of Busey’s operating segments are the same as those described in the summary of significant accounting policies in “Note 1. Significant Accounting Policies” of Busey’s 2025 Annual Report. Busey accounts for intersegment revenue and transfers at current market prices.


	As of March 31, 2026
(dollars in thousands)	Banking		Wealth Management		FirsTech		Other		Total
Goodwill	$	359,263	$	14,108	$	8,992	$	—	$	382,363
Total assets	17,835,924		155,714		44,964		20		18,036,622


	As of December 31, 2025
(dollars in thousands)	Banking		Wealth Management		FirsTech		Other		Total
Goodwill	$	360,180	$	14,108	$	8,992	$	—	$	383,280
Total assets	17,880,797		152,422		45,373		26,144		18,104,736

Financial results by operating segment, including significant expense categories provided to the chief operating decision maker, are summarized below:


	Three Months Ended March 31, 2026
(dollars in thousands)	Banking		Wealth Management		FirsTech		Other		Total
Interest income	$	225,407	$	—	$	—	$	78	$	225,485
Intersegment interest income	—		—		15		(15)		—
Interest expense	68,874		—		—		2,642		71,516
Intersegment interest expense	504		—		—		(504)		—
Net interest income	156,029		—		15		(2,075)		153,969
Provision for credit losses	3,058		—		—		—		3,058
Net interest income after provision for credit losses	152,971		—		15		(2,075)		150,911

Noninterest income
Wealth management fees	—		19,370		—		—		19,370
Payment technology solutions	—		—		5,077		—		5,077
Treasury management services	4,826		—		—		—		4,826
Card services and ATM fees	4,646		—		—		—		4,646
Other service charges on deposit accounts	1,506		—		—		—		1,506
All other noninterest income	7,621		157		—		(938)		6,840
Intersegment noninterest income	2,833		—		561		(3,394)		—
Noninterest income	21,432		19,527		5,638		(4,332)		42,265

Revenue	177,461		19,527		5,653		(6,407)		196,234

Noninterest expense
Salaries, wages, and employee benefits	71,707		8,866		4,657		—		85,230
Data processing	8,182		763		886		33		9,864
Amortization of intangible assets	4,110		181		—		—		4,291
Interchange expense	—		—		1,116		—		1,116
All other noninterest expense	25,682		852		676		1,808		29,018
Intersegment noninterest expense	679		750		540		(1,969)		—
Noninterest expense	110,360		11,412		7,875		(128)		129,519

Income (loss) before income taxes	64,043		8,115		(2,222)		(6,279)		63,657
Income taxes	13,803		1,948		(542)		(1,533)		13,676
Net income (loss)	$	50,240	$	6,167	$	(1,680)	$	(4,746)	$	49,981


	Three Months Ended March 31, 2025
(dollars in thousands)	Banking		Wealth Management		FirsTech		Other		Total
Interest income	$	166,812	$	—	$	—	$	3	$	166,815
Intersegment interest income	—		—		13		(13)		—
Interest expense	58,517		—		—		4,567		63,084
Intersegment interest expense	491		—		—		(491)		—
Net interest income	107,804		—		13		(4,086)		103,731
Provision for credit losses	45,593		—		—		—		45,593
Net interest income after provision for credit losses	62,211		—		13		(4,086)		58,138

Noninterest income
Wealth management fees	—		17,364		—		—		17,364
Payment technology solutions	—		—		5,073		—		5,073
Treasury management services	3,017		—		—		—		3,017
Card services and ATM fees	3,709		—		—		—		3,709
Other service charges on deposit accounts	1,533		—		—		—		1,533
All other noninterest income	(9,379)		202		(2)		(294)		(9,473)
Intersegment noninterest income	352		—		345		(697)		—
Noninterest income	(768)		17,566		5,416		(991)		21,223

Revenue	107,036		17,566		5,429		(5,077)		124,954

Noninterest expense
Salaries, wages, and employee benefits	46,726		7,031		2,481		11,325		67,563
Data processing	7,949		593		937		96		9,575
Amortization of intangible assets	2,841		242		—		—		3,083
Interchange expense	—		—		1,343		—		1,343
All other noninterest expense	19,825		737		617		9,287		30,466
Intersegment noninterest expense	4,665		780		369		(5,814)		—
Noninterest expense	82,006		9,383		5,747		14,894		112,030

Income (loss) before income taxes	(20,563)		8,183		(318)		(19,971)		(32,669)
Income taxes	(870)		1,964		(79)		(3,694)		(2,679)
Net income (loss)	$	(19,693)	$	6,219	$	(239)	$	(16,277)	$	(29,990)

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147482810/280-10-50-26B

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-Publisher FASB
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Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-41

+ Details

FAIR VALUE MEASUREMENTS - Schedule of Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis (Details) - Fair Value, Nonrecurring $ in Thousands	Mar. 31, 2026 USD ($)	Dec. 31, 2025 USD ($)
Fair Value
Loans evaluated individually, net of related allowance	$ 17,658	$ 19,604
Bank property held for sale with impairment	1,661	1,855
OREO and other repossessed assets with subsequent impairment
Fair Value
OREO and other repossessed assets with subsequent impairment	3,171	4,409
Level 3 Inputs
Fair Value
Loans evaluated individually, net of related allowance	17,658	19,604
Bank property held for sale with impairment	1,661	1,855
Level 3 Inputs \| OREO and other repossessed assets with subsequent impairment
Fair Value
OREO and other repossessed assets with subsequent impairment	3,171	4,409
Level 3 Inputs \| Appraisal of collateral
Fair Value
Loans evaluated individually, net of related allowance	17,658	19,604
Level 3 Inputs \| Appraisal of collateral \| OREO and other repossessed assets with subsequent impairment
Fair Value
OREO and other repossessed assets with subsequent impairment	$ 3,171	$ 4,409
Level 3 Inputs \| Appraisal of collateral \| Minimum \| Measurement Input, Comparability Adjustment
Range (Weighted Average)
Loans evaluated individually, net of related allowance	(0.016)	(0.016)
Level 3 Inputs \| Appraisal of collateral \| Minimum \| Measurement Input, Comparability Adjustment \| OREO and other repossessed assets with subsequent impairment
Range (Weighted Average)
OREO and other repossessed assets with subsequent impairment	(0.035)	(0.028)
Level 3 Inputs \| Appraisal of collateral \| Maximum \| Measurement Input, Comparability Adjustment
Range (Weighted Average)
Loans evaluated individually, net of related allowance	(1.000)	(1.000)
Level 3 Inputs \| Appraisal of collateral \| Maximum \| Measurement Input, Comparability Adjustment \| OREO and other repossessed assets with subsequent impairment
Range (Weighted Average)
OREO and other repossessed assets with subsequent impairment	(0.241)	(0.241)
Level 3 Inputs \| Appraisal of collateral \| Weighted Average \| Measurement Input, Comparability Adjustment
Range (Weighted Average)
Loans evaluated individually, net of related allowance	(0.414)	(0.446)
Level 3 Inputs \| Appraisal of collateral \| Weighted Average \| Measurement Input, Comparability Adjustment \| OREO and other repossessed assets with subsequent impairment
Range (Weighted Average)
OREO and other repossessed assets with subsequent impairment	(0.039)	(0.045)
Level 3 Inputs \| Appraisal of collateral or real estate listing price
Fair Value
Bank property held for sale with impairment	$ 1,661	$ 1,855
Level 3 Inputs \| Appraisal of collateral or real estate listing price \| Minimum \| Measurement Input, Comparability Adjustment
Range (Weighted Average)
Bank property held for sale with impairment	(0.090)	(0.090)
Level 3 Inputs \| Appraisal of collateral or real estate listing price \| Maximum \| Measurement Input, Comparability Adjustment
Range (Weighted Average)
Bank property held for sale with impairment	(0.461)	(0.580)
Level 3 Inputs \| Appraisal of collateral or real estate listing price \| Weighted Average \| Measurement Input, Comparability Adjustment
Range (Weighted Average)
Bank property held for sale with impairment	(0.361)	(0.394)

TAX CREDIT INVESTMENTS AND OTHER INVESTMENTS IN UNCONSOLIDATED ENTITIES

3 Months Ended

Mar. 31, 2026

Investments, All Other Investments [Abstract]

TAX CREDIT INVESTMENTS AND OTHER INVESTMENTS IN UNCONSOLIDATED ENTITIES

NOTE 9. TAX CREDIT INVESTMENTS AND OTHER INVESTMENTS IN UNCONSOLIDATED ENTITIES

Busey’s investments in unconsolidated entities and related unfunded investment obligations are reflected in other assets and other liabilities on the Consolidated Balance Sheets (Unaudited), and are summarized in the table below for the periods indicated:


		As of
(dollars in thousands)	Location	March 31, 2026		December 31, 2025
Investments in unconsolidated entities
Tax credit investments	Other assets	$	129,282	$	119,634
Other investments in unconsolidated entities	Other assets	46,314		46,361
Investments in unconsolidated entities		$	175,596	$	165,995

Unfunded investment obligations	Other liabilities	$	71,479	$	68,690

Busey applies the proportional amortization method in accounting for investments in tax-advantaged projects. Income tax credits and other benefits related to these investments, along with investment amortization, are included as a component of Busey’s estimated annual effective tax rate used for the calculation of income taxes presented on the Consolidated Statements of Income (Unaudited). Actual amounts of income tax credits and other benefits, along with the investment amortization, are presented in the table below:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Income tax credits and other tax benefits		$	4,925	$	4,589
Amortization of investments in tax-advantaged projects		4,432		4,108

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 2,468,982	$ 1,383,269
Ending balance	2,413,022	2,179,606
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(124,473)	(207,039)
Ending balance	(135,553)	(172,810)
Unrealized Gains (Losses) on Debt Securities Available For Sale and Unrealized Gains (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Unrealized holding gains (losses), net	(12,851)	21,222
Amounts reclassified from AOCI, net and amortization of unrecognized losses on securities transferred to held to maturity	1,034	12,879
Unrealized Gains (Losses) on Debt Securities Available For Sale
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(98,693)	(165,680)
Unrealized holding gains (losses), net	(10,068)	16,581
Amounts reclassified from AOCI, net and amortization of unrecognized losses on securities transferred to held to maturity	(18)	11,374
Ending balance	(108,779)	(137,725)
Unrealized Gains (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(7,616)	(19,805)
Unrealized holding gains (losses), net	(2,783)	4,641
Amounts reclassified from AOCI, net and amortization of unrecognized losses on securities transferred to held to maturity	1,052	1,505
Ending balance	(9,347)	(13,659)
Unrecognized Gains (Losses) on Debt Securities Held to Maturity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(18,164)	(21,554)
Amounts reclassified from AOCI, net and amortization of unrecognized losses on securities transferred to held to maturity	737	128
Ending balance	$ (17,427)	$ (21,426)

- Definition

Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

STOCK-BASED COMPENSATION - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total stock-based compensation expense	$ 4,136	$ 3,394
Salaries, wages, and employee benefits
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total stock-based compensation expense	3,930	3,217
Other expense
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total stock-based compensation expense	$ 206	$ 177

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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+ Details

STOCK-BASED COMPENSATION -Schedule of Shares Remaining Available For Issuance Under Busey’s Equity Compensation Plans (Details)	Mar. 31, 2026 shares
2020 Equity Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares Remaining Available for Issuance Pursuant to the Plan (in shares)	746,172
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares Remaining Available for Issuance Pursuant to the Plan (in shares)	254,688

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

LEASES - Schedule of Lease-Related Balances (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Right of use assets:
Operating leases	$ 32,104	$ 30,204
Finance leases	5,076	5,155
Total right of use assets	37,180	35,359
Lease liabilities:
Operating leases	35,749	32,597
Finance leases	6,178	6,223
Total lease liabilities	41,927	38,820
Net of accumulated amortization	$ 300	$ 300
Weighted average remaining lease terms:
Operating leases	7 years 6 months 21 days	7 years 4 months 28 days
Finance leases	16 years 3 days	16 years 3 months 3 days
Weighted average discount rates:
Operating leases	4.28%	4.24%
Finance leases	5.10%	5.10%

DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Interest Rate Swaps Recorded in Noninterest Expense (Details) - Interest Rate Swap - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Derivative [Line Items]
Net change in fair value of interest rate swaps	$ 0	$ 0
Noninterest expense
Derivative [Line Items]
Gain, receive-fixed, pay-floating	(3,116)	3,034
Loss, receive-floating, pay-fixed	$ 3,116	$ (3,034)

FAIR VALUE MEASUREMENTS

3 Months Ended

Mar. 31, 2026

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

NOTE 13. FAIR VALUE MEASUREMENTS

The fair value of an asset or liability is the price that would be received by selling that asset or paid in transferring that liability (exit price) in an orderly transaction occurring in the principal market (or most advantageous market in the absence of a principal market) for such asset or liability. ASC Topic 820 “Fair Value Measurement” establishes a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The fair value hierarchy is as follows:

•Level 1 Inputs—Unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.

•Level 2 Inputs—Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, volatility, prepayment speeds, credit risks, etc.) or inputs that are derived principally from or corroborated by market data by correlation or other means.

•Level 3 Inputs—Unobservable inputs for estimating the fair values of assets or liabilities that reflect the Company’s own assumptions about the assumptions that market participants would use in pricing the assets or liabilities.

A description of the valuation methodologies used for instruments measured at fair value, as well as the general classification of such instruments pursuant to the valuation hierarchy, is set forth below. These valuation methodologies were applied to Busey’s assets and liabilities that are carried at fair value.

In general, fair value estimates are based upon quoted market prices, when available. If such quoted market prices are not available, fair values are estimated utilizing independent valuation techniques that consider identical or similar securities for which significant assumptions are derived primarily from or corroborated by observable data. Valuation adjustments may be made to ensure that financial instruments are recorded at their estimated fair values. These adjustments may include amounts to reflect, among other things, counterparty credit quality and the company's creditworthiness as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. While management believes Busey's valuation methodologies are appropriate and consistent with other market participants, the use of different methodologies or assumptions to estimate the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date.

Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis

Debt Securities Available for Sale

Debt securities classified as available for sale are reported at fair value, which is estimated using Level 2 inputs. Busey obtains fair value measurements from an independent pricing service. The independent pricing service utilizes evaluated pricing models that vary by asset class and incorporate available trade, bid, and other market information. Because many fixed income securities do not trade on a daily basis, the independent pricing service applies available information to prepare evaluations, with a focus on observable market data such as benchmark curves, benchmarking of like securities, sector groupings, and matrix pricing.

The independent pricing service uses model processes, such as the Option Adjusted Spread model, to assess interest rate impact and develop prepayment scenarios. Models and processes take into account market conventions. For each asset class, a team of evaluators gathers information from market sources and integrates relevant credit information, perceived market movements, and sector news into the evaluated pricing applications and models.

Market inputs that the independent pricing service normally seeks for evaluations of securities, listed in approximate order of priority, include: benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data including market research publications. The independent pricing service also monitors market indicators, industry, and economic events. For certain security types, additional inputs may be used or some of the market inputs may not be applicable. Evaluators may prioritize inputs differently on any given day for any security based on market conditions, and not all inputs listed are available for use in the evaluation process for each security evaluation on a given day. Because the data utilized was observable, the securities have been classified as Level 2.

Equity Securities

Equity securities are reported at fair value, which is estimated using Level 1 or Level 2 inputs. Fair value measurements of mutual funds or stock in active markets are estimated using unadjusted quoted prices for identical assets at the measurement date and are classified as Level 1. Fair value measurements of stock that are not active use quoted prices for identical or similar assets in markets and are classified as Level 2.

Derivative Assets and Derivative Liabilities

Busey’s derivative assets and derivative liabilities are reported at fair value, which is measured using Level 2 or Level 3 inputs. Fair values of derivative assets and liabilities are estimated based on prices that are obtained from a third-party which uses observable market inputs and, with the exception of risk participation agreements, are classified as Level 2. Due to the significance of unobservable inputs, derivative assets and liabilities related to risk participation agreements are classified as Level 3.

The following tables summarize financial assets and financial liabilities measured at estimated fair value on a recurring basis:


	As of March 31, 2026
(dollars in thousands)	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Debt securities available for sale:

Obligations of U.S. government corporations and agencies	$	—	$	109,006	$	—	$	109,006
Obligations of states and political subdivisions	—		260,054		—		260,054
Asset-backed securities	—		246,506		—		246,506
Commercial mortgage-backed securities	—		149,455		—		149,455
Residential mortgage-backed securities	—		1,409,671		—		1,409,671
Corporate debt securities	—		40,575		—		40,575
Equity securities	131		13,820		—		13,951
Derivative assets	—		26,589		22		26,611
Derivative liabilities	—		39,917		48		39,965


	As of December 31, 2025
(dollars in thousands)	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Debt securities available for sale:

Obligations of U.S. government corporations and agencies	$	—	$	112,046	$	—	$	112,046
Obligations of states and political subdivisions	—		263,873		—		263,873
Asset-backed securities	—		265,580		—		265,580
Commercial mortgage-backed securities	—		132,942		—		132,942
Residential mortgage-backed securities	—		1,344,416		—		1,344,416
Corporate debt securities	—		43,691		—		43,691
Equity securities	155		14,761		—		14,916
Derivative assets	—		30,902		30		30,932
Derivative liabilities	—		42,155		65		42,220

Activity for Busey's risk participation agreements, which are measured at estimated fair value on a recurring basis using Level 3 inputs, is summarized in the table below:


		Three Months Ended March 31,
(dollars in thousands)	Location		2026		2025
Beginning Balance			$	(35)	$	5
Gains (losses) recognized in earnings	Other noninterest expense		9		2
Gains (losses) recognized in earnings1	Other noninterest income		—		(11)


Sales			—		6
Assumed in business combinations2			—		(41)




Ending Balance			$	(26)	$	(39)

___________________________________________

1.CrossFirst Bank, which Busey operated as a separate banking subsidiary from the time of its acquisition on March 1, 2025, until it was merged with and into Busey Bank on June 20, 2025, recorded gains and losses on its risk participation agreements as other noninterest income. Throughout 2025, Busey accounted for the CrossFirst portfolio of risk participation agreements consistent with this methodology. Beginning in 2026, gains and losses recognized on Busey’s full portfolio of risk participation agreements, is recorded as other noninterest expense.

2.Represents risk participation agreements assumed in the CrossFirst acquisition.

Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis

Certain financial assets and financial liabilities are measured at estimated fair value on a non-recurring basis; that is, the instruments are not measured at estimated fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment).

Loans Evaluated Individually

Busey does not record portfolio loans at estimated fair value on a recurring basis. However, periodically, a loan is evaluated individually and is reported at the estimated fair value of the underlying collateral, less estimated costs to sell, if repayment is expected solely from the collateral. If the estimated collateral value is not sufficient, a specific reserve is recorded. Collateral values are estimated using a combination of observable inputs, including recent appraisals, and unobservable inputs based on customized discounting criteria. Due to the significance of unobservable inputs, fair values of individually evaluated collateral dependent loans have been classified as Level 3.

OREO and Other Repossessed Assets

Non-financial assets measured at fair value, upon initial recognition or subsequent impairment, include OREO and other repossessed assets. OREO properties and other repossessed assets are measured using a combination of observable inputs, including recent appraisals, and unobservable inputs. Due to the significance of unobservable inputs, the estimated fair values of all OREO and other repossessed assets have been classified as Level 3.

Bank Property Held for Sale

Bank property held for sale represents certain banking center office buildings which Busey has closed and consolidated with other existing banking centers. Bank property held for sale is measured at the lower of amortized cost or estimated fair value less estimated costs to sell. Fair value estimates were based upon discounted appraisals or real estate listing prices. Due to the significance of unobservable inputs, estimated fair values of all bank property held for sale have been classified as Level 3. Bank property held for sale is included in premises and equipment, net on Busey’s Consolidated Balance Sheets (Unaudited).

The following tables summarize financial assets and financial liabilities measured at estimated fair value on a non-recurring basis:


	As of March 31, 2026
(dollars in thousands)	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Loans evaluated individually, net of related allowance	$	—	$	—	$	17,658	$	17,658
OREO and other repossessed assets with subsequent impairment	—		—		3,171		3,171
Bank property held for sale with impairment	—		—		1,661		1,661


	As of December 31, 2025
(dollars in thousands)	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Loans evaluated individually, net of related allowance	$	—	$	—	$	19,604	$	19,604
OREO and other repossessed assets with subsequent impairment	—		—		4,409		4,409
Bank property held for sale with impairment	—		—		1,855		1,855

The following tables present additional quantitative information about assets measured at estimated fair value on a non-recurring basis using Level 3 inputs:

As of March 31, 2026

(dollars in thousands)

Fair Value

Valuation
Techniques

Unobservable
Input

Range
(Weighted Average)

Loans evaluated individually, net of related allowance

17,658

Appraisal of collateral

Appraisal adjustments

-1.6% to -100.0%

(-41.4)%

OREO and other repossessed assets with subsequent impairment

3,171

Appraisal of collateral

Appraisal adjustments

-3.5% to -24.1%

(-3.9)%

Bank property held for sale with impairment

1,661

Appraisal of collateral or real estate listing price

Appraisal adjustments

-9.0% to -46.1%

(-36.1)%

As of December 31, 2025

(dollars in thousands)

Fair Value

Valuation
Techniques

Unobservable
Input

Range
(Weighted Average)

Loans evaluated individually, net of related allowance

19,604

Appraisal of collateral

Appraisal adjustments

-1.6% to -100.0%

(-44.6)%

OREO and other repossessed assets with subsequent impairment

4,409

Appraisal of collateral

Appraisal adjustments

-2.8% to -24.1%

(-4.5)%

Bank property held for sale with impairment

1,855

Appraisal of collateral or real estate listing price

Appraisal adjustments

-9.0% to -58.0%

(-39.4)%

Financial Assets and Financial Liabilities That Are Not Carried at Fair Value

Fair values of financial instruments that are not carried at fair value on Busey’s Consolidated Balance Sheets (Unaudited) were estimated as follows:


	As of March 31, 2026				As of December 31, 2025
(dollars in thousands)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Financial assets
Level 1 inputs:
Cash and cash equivalents	$	288,462	$	288,462	$	280,227	$	280,227
Level 2 inputs:
Interest-bearing time deposits in other banks	13,725		11,791		13,825		11,880
Debt securities held to maturity	725,540		601,074		746,385		625,957
Loans held for sale	5,224		5,255		5,752		5,886
Restricted bank stock	81,722		81,722		77,006		77,006
Accrued interest receivable	73,110		73,110		71,788		71,788
Level 3 inputs:
Portfolio loans, net	13,290,836		13,356,367		13,393,776		13,472,907
Mortgage servicing rights	1,577		5,239		1,459		5,176
Other servicing rights	2,086		2,265		2,086		2,193

Financial liabilities
Level 2 inputs:
Time deposits	$	2,366,141	$	2,358,640	$	2,429,890	$	2,425,290
Securities sold under agreements to repurchase	156,364		156,364		166,929		166,929
Short-term borrowings	170,000		170,000		—		—
Long-term borrowings	123,466		122,835		113,806		113,853
Junior subordinated debt owed to unconsolidated trusts	77,400		73,037		77,328		71,407
Accrued interest payable	26,186		26,186		25,372		25,372
Level 3 inputs:

Subordinated notes, net of unamortized issuance costs	99,499		96,750		99,395		94,500

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 107
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-107

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 100
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 940
-SubTopic 820
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478119/940-820-50-1

+ Details

DEPOSITS - Schedule of Maturities of Time Deposits (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Time deposits by schedule of maturities
Remainder of 2026	$ 2,065,390
2027	279,010
2028	12,813
2029	4,665
2030	3,009
2031	1,244
Thereafter	10
Time deposits	$ 2,366,141	$ 2,429,890

Cover Page - shares	3 Months Ended
Cover Page - shares	Mar. 31, 2026	May 07, 2026
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2026
Document Transition Report	false
Entity File Number	0-15950
Entity Registrant Name	FIRST BUSEY CORPORATION
Entity Incorporation, State or Country Code	NV
Entity Tax Identification Number	37-1078406
Entity Address, Address Line One	11440 Tomahawk Creek Parkway
Entity Address, City or Town	Leawood
Entity Address, State or Province	KS
Entity Address, Postal Zip Code	66211
City Area Code	(217)
Local Phone Number	365-4544
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		84,577,160
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2026
Document Fiscal Period Focus	Q1
Entity Central Index Key	0000314489
Amendment Flag	false
Common Stock, $0.001 par value
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.001 par value
Trading Symbol	BUSE
Security Exchange Name	NASDAQ
Depositary Shares, each representing a 1/40th interest in a share of 8.25% Fixed-Rate Series B Non-Cumulative Perpetual Preferred Stock, $0.001 par value
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares, each representing a 1/40th interest in a share of 8.25% Fixed-Rate Series B Non-Cumulative Perpetual Preferred Stock
Trading Symbol	BUSEP
Security Exchange Name	NASDAQ

FAIR VALUE MEASUREMENTS - Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	$ 2,215,267	$ 2,162,548
Equity securities	13,951	14,916
Obligations of U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	109,006	112,046
Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	260,054	263,873
Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	246,506	265,580
Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	149,455	132,942
Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	1,409,671	1,344,416
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	40,575	43,691
Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	26,611	30,932
Derivative liabilities	39,965	42,220
Fair Value, Recurring \| Obligations of U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	109,006	112,046
Fair Value, Recurring \| Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	260,054	263,873
Fair Value, Recurring \| Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	246,506	265,580
Fair Value, Recurring \| Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	149,455	132,942
Fair Value, Recurring \| Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	1,409,671	1,344,416
Fair Value, Recurring \| Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	40,575	43,691
Fair Value, Recurring \| Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	13,951	14,916
Fair Value, Recurring \| Level 1 Inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Fair Value, Recurring \| Level 1 Inputs \| Obligations of U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Fair Value, Recurring \| Level 1 Inputs \| Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Fair Value, Recurring \| Level 1 Inputs \| Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Fair Value, Recurring \| Level 1 Inputs \| Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Fair Value, Recurring \| Level 1 Inputs \| Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Fair Value, Recurring \| Level 1 Inputs \| Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Fair Value, Recurring \| Level 1 Inputs \| Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	131	155
Fair Value, Recurring \| Level 2 Inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	26,589	30,902
Derivative liabilities	39,917	42,155
Fair Value, Recurring \| Level 2 Inputs \| Obligations of U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	109,006	112,046
Fair Value, Recurring \| Level 2 Inputs \| Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	260,054	263,873
Fair Value, Recurring \| Level 2 Inputs \| Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	246,506	265,580
Fair Value, Recurring \| Level 2 Inputs \| Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	149,455	132,942
Fair Value, Recurring \| Level 2 Inputs \| Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	1,409,671	1,344,416
Fair Value, Recurring \| Level 2 Inputs \| Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	40,575	43,691
Fair Value, Recurring \| Level 2 Inputs \| Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	13,820	14,761
Fair Value, Recurring \| Level 3 Inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	22	30
Derivative liabilities	48	65
Fair Value, Recurring \| Level 3 Inputs \| Obligations of U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Fair Value, Recurring \| Level 3 Inputs \| Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Fair Value, Recurring \| Level 3 Inputs \| Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Fair Value, Recurring \| Level 3 Inputs \| Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Fair Value, Recurring \| Level 3 Inputs \| Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Fair Value, Recurring \| Level 3 Inputs \| Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Fair Value, Recurring \| Level 3 Inputs \| Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	$ 0	$ 0

EARNINGS PER COMMON SHARE (Tables)

3 Months Ended

Mar. 31, 2026

Earnings Per Share [Abstract]

Schedule of Computation of Earnings Per Common Share

Earnings per common share have been computed as follows:


	Three Months Ended March 31,
(dollars in thousands, except per share amounts)		2026		20251
Net income (loss)		$	49,981	$	(29,990)
Dividends on preferred stock		(4,589)		—
Net income (loss) available to common stockholders		$	45,392	$	(29,990)

Weighted average number of common shares outstanding, basic		86,692,001		68,517,647








Dilutive effect of outstanding equity-based awards		1,139,294		—
Weighted average number of common shares outstanding, diluted		87,831,295		68,517,647

Basic earnings (loss) per common share		$	0.52	$	(0.44)
Diluted earnings (loss) per common share		$	0.52	$	(0.44)

Anti-dilutive equity-based awards		—		2,794,422

___________________________________________

LEASES - Schedule of Future Undiscounted Lease Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Operating Leases
Remainder of 2026	$ 5,091
2027	6,470
2028	5,941
2029	4,958
2030	4,057
2031	3,898
Thereafter	11,648
Total undiscounted cash flows	42,063
Less: Amounts representing interest	6,314
Present value of net future minimum lease payments	35,749	$ 32,597
Finance Leases
Remainder of 2026	368
2027	527
2028	540
2029	540
2030	540
2031	540
Thereafter	6,085
Total undiscounted cash flows	9,140
Less: Amounts representing interest	2,962
Present value of net future minimum lease payments	$ 6,178	$ 6,223

DEPOSITS

3 Months Ended

Mar. 31, 2026

Deposits [Abstract]

DEPOSITS

NOTE 6. DEPOSITS

The composition of Busey’s deposits is presented in the table below:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Deposits
Noninterest-bearing demand deposits	$	3,526,036	$	3,659,421
Interest-bearing transaction deposits	3,129,186		3,119,475
Saving deposits and money market deposits	5,714,697		5,697,172
Time deposits	2,366,141		2,429,890
Total deposits	$	14,736,060	$	14,905,958

Additional information about Busey’s deposits is presented in the table below:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Brokered interest-bearing transaction deposits	$	50,119	$	50,136
Brokered savings deposits and money market deposits	10,004		10,000
Brokered time deposits	—		10,004
Aggregate amount of time deposits with a minimum denomination of $100,000	1,637,485		1,674,862
Aggregate amount of time deposits with a minimum denomination that meets or exceeds the FDIC insurance limit of $250,000	865,493		876,207

Scheduled maturities of time deposits are presented in the table below:


(dollars in thousands)	As of March 31, 2026
Time deposits by schedule of maturities
Remainder of 2026	$	2,065,390
2027	279,010
2028	12,813
2029	4,665
2030	3,009
2031	1,244
Thereafter	10
Time deposits	$	2,366,141

DERIVATIVE FINANCIAL INSTRUMENTS (Tables)

3 Months Ended

Mar. 31, 2026

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Financial Instruments Owned and Pledged as Collateral


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Pledged loans
FHLB	$	7,199,169	$	5,051,512
Federal Reserve Bank	1,923,484		1,854,423
Total pledged loans	$	9,122,653	$	6,905,935

To secure its obligations under derivative contracts, Busey pledged cash and held collateral as follows:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Cash pledged to secure obligations under derivative contracts	$	14,400	$	14,400
Collateral held to secure obligations under derivative contracts	6,750		5,050

Schedule of the Interest-Rate Swaps Designated as Cash Flow Hedges

A summary of the interest-rate swaps designated as cash flow hedges is presented below:


		As of
(dollars in thousands)	Location	March 31, 2026			December 31, 2025
Prime Loan Swap
Notional amount		$	300,000		$	300,000
Weighted average rate: receive-fixed		4.81		%	4.81		%
Weighted average variable Prime pay rates		6.75		%	6.81		%
Weighted average maturity		2.85 years			3.10 years

SOFR Loan Swaps
Notional amount		$	400,000		$	200,000
Weighted average rate: receive-fixed		3.71		%	3.78		%
Weighted average variable 1-month CME Term SOFR pay rates1		3.67		%	3.82		%
Weighted average maturity		5.18 years			3.76 years

Gross aggregate fair value of the swaps
Gross aggregate fair value of swap assets	Other assets	$	1,776		$	3,215
Gross aggregate fair value of swap liabilities	Other liabilities	15,421			14,589

Balances carried in AOCI
Unrealized gains (losses) on cash flow hedges, net of tax	AOCI	$	(9,347)		$	(7,616)

___________________________________________

1.A pay rate is not yet applicable for a 6-month forward-starting SOFR loan swap with a notional amount of $200 million, which was entered into during the first quarter of 2026, so this SOFR loan swap was excluded from the calculation of the weighted average pay rate.

Schedule of Reclassification of Unrealized Gains and Losses from OCI

During the next 12 months, Busey expects to reclassify unrealized gains and losses from OCI to interest income as shown in the following table. Amounts actually recognized could differ from these expectations due to changes in interest rates, hedge de-designations, and the addition of other hedges subsequent to March 31, 2026.


(dollars in thousands)	As of March 31, 2026

Unrealized gains expected to be reclassified from OCI to interest income	$	481

Schedule of Interest Income (Expense) Recorded on Swap Transactions

Changes in interest income recorded on these swap transactions is presented in the following table:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025

Decrease in interest income on swap transactions		$	(1,403)	$	(2,060)

Schedule of Net Gains (Losses) Relating to these Derivative Instruments

Net gains and losses relating to cash flow derivative instruments that were recorded in OCI on the Consolidated Statements of Income (Unaudited) are presented in the table below:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Unrealized gains (losses) on cash flow hedges
Net gains (losses) recognized in OCI, net of tax		$	(2,783)	$	4,641
Losses reclassified from OCI to interest income, net of tax		1,052		1,505

Net change in unrealized gains (losses) on cash flow hedges, net of tax		$	(1,731)	$	6,146

Changes in fair value of these derivative assets and derivative liabilities were recorded in noninterest expense on the Consolidated Statements of Income (Unaudited) and are summarized as follows:


		Three Months Ended March 31,
(dollars in thousands)	Location		2026		2025
Interest rate swaps
Receive-fixed, pay-floating	Noninterest expense		$	(3,116)	$	3,034
Receive-floating, pay-fixed	Noninterest expense		3,116		(3,034)
Net change in fair value of interest rate swaps			$	—	$	—

Gains and losses relating to these derivative instruments are reported in noninterest income, and are summarized as follows:


		Three Months Ended March 31,
(dollars in thousands)	Location		2026		2025
Net gains (losses) on mortgage banking derivatives
Gains (losses) on interest rate lock commitments	Mortgage revenue		$	44	$	242
Gains (losses) on forward sales commitments	Mortgage revenue		96		(87)


Net gains (losses) on mortgage banking derivatives			$	140	$	155

Schedule of Fair Values of Derivative Assets and Liabilities Recorded in Consolidated Balance Sheet

Amounts and fair values of derivative assets and derivative liabilities related to customer interest rate swaps recorded on the Consolidated Balance Sheets (Unaudited) are summarized as follows:


		As of March 31, 2026				As of December 31, 2025
(dollars in thousands)	Location	Notional Amount		Fair Value		Notional Amount		Fair Value
Derivative assets not designated as hedging instruments
Interest rate swaps: receive-fixed, pay-floating	Other assets	$	740,117	$	7,355	$	703,286	$	11,542
Interest rate swaps: receive-floating, pay-fixed	Other assets	531,572		17,135		456,973		15,998
Derivative assets not designated as hedging instruments		$	1,271,689	$	24,490	$	1,160,259	$	27,540

Derivative liabilities not designated as hedging instruments
Interest rate swaps: receive-fixed, pay-floating	Other liabilities	$	531,572	$	17,135	$	456,973	$	15,998
Interest rate swaps: receive-floating, pay-fixed	Other liabilities	740,117		7,355		703,286		11,542
Derivative liabilities not designated as hedging instruments		$	1,271,689	$	24,490	$	1,160,259	$	27,540

Amounts and fair values of mortgage banking derivatives included on the Consolidated Balance Sheets (Unaudited) are summarized as follows:


		As of March 31, 2026				As of December 31, 2025
(dollars in thousands)	Location	Notional Amount		Fair Value		Notional Amount		Fair Value
Mortgage banking derivative assets
Interest rate lock commitments	Other assets	$	3,139	$	42	$	6,159	$	145
Forward sales commitments	Other assets	6,861		70		1,520		2
Mortgage banking derivative assets		$	10,000	$	112	$	7,679	$	147

Mortgage banking derivative liabilities

Forward sales commitments1	Other liabilities	$	201	$	—	$	9,278	$	26
Mortgage banking derivative liabilities		$	201	$	—	$	9,278	$	26

___________________________________________

1.The fair value of forward sales commitments in a liability position was immaterial, rounding to zero thousand.

Schedule of Notional Amount and Fair Value of Risk Participation Agreement

The risk participation agreements mature between May 2026 and October 2033, and are summarized as follows:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Risk participation agreements purchased
Number of risk participation agreements	12		12
Notional amount	$	74,942	$	74,590
Fair value	22		30

Risk participation agreements sold
Number of risk participation agreements	13		13
Notional amount	$	108,242	$	108,743
Fair value	48		65

Schedule of Foreign Currency Forward Contracts

Amounts and fair values of derivative assets and derivative liabilities related to foreign currency contracts recorded on the Consolidated Balance Sheets (Unaudited) are summarized as follows:


		As of March 31, 2026				As of December 31, 2025
(dollars in thousands)	Location	Notional Amount		Fair Value		Notional Amount		Fair Value
Foreign currency exchange forward contracts
Customer contracts	Other assets	$	3,531	$	211	$	—	$	—
Third-party dealer contracts	Other liabilities	629		6		—		—

BUSINESS COMBINATIONS (Tables)

3 Months Ended

Mar. 31, 2026

Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract]

Schedule of Estimated Acquisition-Date Fair Values of the Assets Acquired and Liabilities Assumed

Acquisition-date fair values of the assets acquired and liabilities assumed, as well as the fair value of consideration transferred, were estimated as follows:


	As of
	March 1, 2025
(dollars in thousands)	(final)
Assets acquired
Cash and cash equivalents	$	385,808
Securities	725,622
Portfolio loans, net of ACL	6,023,063
Premises and equipment	69,673

Other intangible assets1	81,783
Other assets	213,352
Total assets acquired	7,499,301

Liabilities assumed
Deposits	6,571,699
Short-term borrowings	11,148
Long-term borrowings	68,922

Junior subordinated debt owed to unconsolidated trusts	2,238

Other liabilities	84,907
Total liabilities assumed	6,738,914

Net assets acquired	$	760,387

Consideration paid
Cash	$	4
Common stock	795,227
Preferred stock	7,750
Replacement awards2	5,999
Total consideration paid	$	808,980

Goodwill	$	48,593

___________________________________________

1.Other intangible assets are being amortized over a period of ten years.

2.Represents the fair value of replacement equity awards issued to CrossFirst associates attributable to pre-combination service.

Schedule of Reconciliation Between the Purchase Price and the Fair Value

The following table provides a reconciliation between the purchase price and the fair value of these financial assets:


	As of
(dollars in thousands)	March 1, 2025

PCD Financial Assets
Gross contractual receivable for PCD financial assets	$	1,539,718
ACL recorded for estimated uncollectible contractual cash flows specific to PCD financial assets	(100,783)
Interest premium (discount) specific to PCD financial assets	(3,063)
Loans previously charged-off prior to acquisition	(110,740)
Fair value of PCD financial assets	$	1,325,132

Busey incurred acquisition-related expenses as follows:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Pre-tax acquisition expenses
CrossFirst1		$	5,244	$	71,490
M&M2		—		108
Pre-tax acquisition expenses		$	5,244	$	71,598

___________________________________________

1.During the three months ended March 31, 2026, Busey recorded acquisition expenses comprising salaries, wages, and employee benefits for multi-year retention agreements, replacement stock-based compensation awards, and relocation related to the CrossFirst acquisition; data processing; and professional fees. During the three months ended March 31, 2025, Busey recorded an initial provision to establish an ACL on non-PCD loans and unfunded commitments and multiple components of noninterest expense including salaries, wages and employee benefits (including equity compensation); data processing; and legal, professional, and consulting costs.

2.During the three months ended March 31, 2025, Busey recorded final acquisition expenses, comprising data processing and consulting expenses related to the acquisition of M&M, which was completed on April 1, 2024.

Of the total acquisition-related expenses, the following legal, professional, and consulting costs were incurred to consummate the merger:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025



Pre-tax costs to consummate the merger		$	119	$	7,144

Schedule of Business Acquisition, Pro Forma Information

Only the acquisition-related expenses that have been recognized are included in net income in the table below:



(dollars in thousands)	Three Months Ended March 31, 2025
Revenue (net interest income plus noninterest income)	$	171,157
Net income	20,241

- Definition

Tabular disclosure of business combination. Includes, but is not limited to, recognized asset and liability.

+ References + Details

PORTFOLIO LOANS - Schedule of Financial Instruments Owned and Pledged as Collateral (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged loans	$ 13,290,836	$ 13,393,776
Total pledged loans
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged loans	9,122,653	6,905,935
FHLB
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged loans	7,199,169	5,051,512
Federal Reserve Bank
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged loans	$ 1,923,484	$ 1,854,423

DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Net Gains (Losses) Recorded in AOCI (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Derivative [Line Items]
Net gains (losses) recognized in OCI, net of tax	$ (3,712)	$ 6,098
Cash Flow Hedging \| Interest Rate Contract
Derivative [Line Items]
Net gains (losses) recognized in OCI, net of tax	(2,783)	4,641
Losses reclassified from OCI to interest income, net of tax	1,052	1,505
Net change in unrealized gains (losses) on cash flow hedges, net of tax	$ (1,731)	$ 6,146

DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Interest Rate Swaps Not Designated as Hedges (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Interest Rate Swap
Derivative assets not designated as hedging instruments
Notional Amount	$ 1,271,689	$ 1,160,259
Fair Value	24,490	27,540
Derivative liabilities not designated as hedging instruments
Notional Amount	1,271,689	1,160,259
Fair Value	24,490	27,540
Interest rate swaps: receive-fixed, pay-floating
Derivative assets not designated as hedging instruments
Notional Amount	740,117	703,286
Fair Value	7,355	11,542
Derivative liabilities not designated as hedging instruments
Notional Amount	531,572	456,973
Fair Value	17,135	15,998
Interest rate swaps: receive-floating, pay-fixed
Derivative assets not designated as hedging instruments
Notional Amount	531,572	456,973
Fair Value	17,135	15,998
Derivative liabilities not designated as hedging instruments
Notional Amount	740,117	703,286
Fair Value	$ 7,355	$ 11,542

DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Risk Participation Agreement (Details) $ in Thousands	Mar. 31, 2026 USD ($) agreement	Dec. 31, 2025 USD ($) agreement
Risk participation agreements purchased
Derivative [Line Items]
Number of risk participation agreements \| agreement	12	12
Notional amount	$ 74,942	$ 74,590
Fair value	$ 22	$ 30
Risk participation agreements sold
Derivative [Line Items]
Number of risk participation agreements \| agreement	13	13
Notional amount	$ 108,242	$ 108,743
Fair value	$ 48	$ 65

CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Statement of Financial Position [Abstract]
Portfolio loans, allowance for credit losses	$ 169,054	$ 174,023
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, liquidation preference	$ 222,750	$ 222,750
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Common stock, shares authorized (in shares)	200,000,000	200,000,000

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Preferred	Common	Additional Paid-in Capital	Retained Earnings	AOCI	Treasury Stock
Beginning balance (in shares) at Dec. 31, 2024		0	56,895,981
Beginning balance at Dec. 31, 2024	$ 1,383,269	$ 0	$ 60	$ 1,360,530	$ 294,054	$ (207,039)	$ (64,336)
Increase (decrease) in shareholders' equity
Net income (loss)	(29,990)				(29,990)
OCI, net of tax	34,229					34,229
Repurchase of stock, including excise tax (in shares)			(220,000)
Repurchase of stock, including excise tax	(4,836)						(4,836)
Net issuance of treasury stock for stock-based compensation plans (in shares)			183,929
Net issuance of treasury stock for stock-based compensation plans	(291)			(5,027)			4,736
Stock issued in acquisition, net of stock issuance costs (in shares)		7,750	33,148,268
Stock issued in acquisition, net of stock issuance costs	808,055		$ 33	808,022
Cash dividends on common stock	(14,224)				(14,224)
Dividend equivalents on RSUs/PSUs/DSUs	0			356	(356)
Stock-based compensation expense	3,394			3,394
Ending balance (in shares) at Mar. 31, 2025		7,750	90,008,178
Ending balance at Mar. 31, 2025	2,179,606	$ 0	$ 93	2,167,275	249,484	(172,810)	(64,436)
Beginning balance (in shares) at Dec. 31, 2025		222,750	87,624,430
Beginning balance at Dec. 31, 2025	2,468,982	$ 0	$ 93	2,375,511	336,707	(124,473)	(118,856)
Increase (decrease) in shareholders' equity
Net income (loss)	49,981				49,981
OCI, net of tax	(11,080)					(11,080)
Repurchase of stock, including excise tax (in shares)			(2,617,400)
Repurchase of stock, including excise tax	(66,149)						(66,149)
Net issuance of treasury stock for stock-based compensation plans (in shares)			500,130
Net issuance of treasury stock for stock-based compensation plans	(5,648)			(18,014)			12,366
Cash dividends on preferred stock	(4,589)				(4,589)
Cash dividends on common stock	(22,611)				(22,611)
Dividend equivalents on RSUs/PSUs/DSUs	0			326	(326)
Stock-based compensation expense	4,136			4,136
Ending balance (in shares) at Mar. 31, 2026		222,750	85,507,160
Ending balance at Mar. 31, 2026	$ 2,413,022	$ 0	$ 93	$ 2,361,959	$ 359,162	$ (135,553)	$ (172,639)

BUSINESS COMBINATIONS - Schedule of Pro Forma Information (Details) - CrossFirst $ in Thousands	3 Months Ended
	Mar. 31, 2025 USD ($)
Business Combination [Line Items]
Revenue (net interest income plus noninterest income)	$ 171,157
Net income	$ 20,241

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
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-Name Accounting Standards Codification
-Section 50
-Paragraph 4
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-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/exampleRef
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

STOCK-BASED COMPENSATION

3 Months Ended

Mar. 31, 2026

Share-Based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION

NOTE 10. STOCK-BASED COMPENSATION

Changes in Busey’s outstanding equity awards are presented in the tables below:


	RSU Awards	PSU Awards1	DSU Awards
Nonvested at December 31, 2025	1,320,537	525,501	41,218
Granted	—	—	—
Dividend equivalents earned	13,929	1,877	435
Vested	(613,166)	(43,283)	(41,653)
Forfeited	(58,395)	(32,086)	—
Nonvested at March 31, 2026	662,905	452,009	—

Vested and outstanding at March 31, 2026	—	—	189,269

___________________________________________

1.Represents target shares at the grant date.


	Options	SSARs
Outstanding at December 31, 2025	15,106	270,398
Exercised	(5,280)	(134,103)
Forfeited	—	—
Expired	—	—
Outstanding at March 31, 2026	9,826	136,295

Exercisable at March 31, 2026	9,826	119,457

Shares remaining available for issuance under Busey’s equity compensation plans as of March 31, 2026, are set forth in the table below:


Plan						Shares Remaining Available for Issuance Pursuant to the Plan
2020 Equity Plan						746,172
ESPP						254,688

Stock-based Compensation Expense

Busey recognized compensation expense related to non-vested equity awards as summarized in the table below:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Stock-based compensation expense
Salaries, wages, and employee benefits1		$	3,930	$	3,217
Other expense2		206		177
Total stock-based compensation expense		$	4,136	$	3,394

___________________________________________

1.Includes expenses for RSUs, PSUs, SSARs, and the ESPP.

2.Represents expenses for DSU awards.

Unamortized compensation expense related to non-vested equity awards is summarized in the table below:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025





Unamortized stock-based compensation	$	9,873	$	15,309

Weighted average period over which expense is to be recognized on awards issued under Busey's 2020 Equity Plan	1.9 years		1.8 years
Weighted average period over which expense is to be recognized on CrossFirst replacement awards	1.1 years		1.2 years

OPERATING SEGMENTS AND RELATED INFORMATION - Narrative (Details)	3 Months Ended
	Mar. 31, 2026 segment bankingCenter
Segment Reporting [Abstract]
Number of reportable segments	3
Number of operating segments	3
Number of full-service locations \| bankingCenter	80

LEASES - Schedule of Lease Costs and Other Lease Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Finance lease costs:
Amortization expense	$ 79	$ 0
Interest expense	78	0
Variable lease costs	10	15
Short-term lease costs	5	12
Total lease cost	1,891	984
Cash flows related to leases
Operating cash flows from operating leases	3,005	1,559
Operating cash flows from finance leases	78	0
Financing cash flows from finance leases	45	0
Right of use assets obtained in exchange for operating lease liabilities	3,248	30,733
CrossFirst
Cash flows related to leases
Right of use assets obtained in exchange for operating lease liabilities		30,700
Net occupancy expense of premises
Operating lease costs:
Premises and Equipment rent expense	1,711	950
Furniture and equipment expenses
Operating lease costs:
Premises and Equipment rent expense	$ 8	$ 7

OUTSTANDING COMMITMENTS AND CONTINGENT LIABILITIES (Tables)

3 Months Ended

Mar. 31, 2026

Commitments and Contingencies Disclosure [Abstract]

Schedule of Contractual Amount of Exposure to Off-Balance-Sheet Risk

A summary of the contractual amount of Busey’s exposure to off-balance sheet risk relating to the Company’s commitments follows:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Off-Balance Sheet Commitments
Commitments to extend credit	$	4,601,629	$	4,696,867
Standby letters of credit	107,974		123,746
Total commitments	$	4,709,603	$	4,820,613

OUTSTANDING COMMITMENTS AND CONTINGENT LIABILITIES - Schedule of Contractual Amount of Exposure to Off-Balance-Sheet Risk (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Credit Commitments and Contingencies
Total commitments	$ 4,709,603	$ 4,820,613
Commitments to extend credit
Credit Commitments and Contingencies
Total commitments	4,601,629	4,696,867
Standby letters of credit
Credit Commitments and Contingencies
Total commitments	$ 107,974	$ 123,746

LEASES - Schedule of Future Minimum Lease Payments (Details) $ in Thousands	Mar. 31, 2026 USD ($)
Rents to be received
Remainder of 2026	$ 587
2027	515
2028	377
2029	197
2030	117
Total lease payments from operating leases	$ 1,793

DEBT SECURITIES - Schedule of Debt Securities in an Unrealized or Unrecognized Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Fair Value
Less than 12 months	$ 493,249	$ 172,731
12 months or more	936,197	958,493
Total	1,429,446	1,131,224
Unrealized Losses
Less than 12 months	(5,324)	(1,252)
12 months or more	(153,256)	(150,930)
Total	(158,580)	(152,182)
Fair Value
12 months or more	601,074	625,957
Total	601,074	625,957
Unrecognized Losses
12 months or more	(124,466)	(120,428)
Total	(124,466)	(120,428)
Obligations of U.S. government corporations and agencies
Fair Value
Less than 12 months	58,527	39,156
12 months or more	31	0
Total	58,558	39,156
Unrealized Losses
Less than 12 months	(244)	(80)
12 months or more	0	0
Total	(244)	(80)
Obligations of states and political subdivisions
Fair Value
Less than 12 months	97,227	28,592
12 months or more	97,076	92,205
Total	194,303	120,797
Unrealized Losses
Less than 12 months	(2,076)	(361)
12 months or more	(10,043)	(9,537)
Total	(12,119)	(9,898)
Asset-backed securities
Fair Value
Less than 12 months	83,728	10,005
12 months or more	0	0
Total	83,728	10,005
Unrealized Losses
Less than 12 months	(322)	(35)
12 months or more	0	0
Total	(322)	(35)
Commercial mortgage-backed securities
Fair Value
Less than 12 months	6,505	4,986
12 months or more	71,215	71,830
Total	77,720	76,816
Unrealized Losses
Less than 12 months	(75)	(48)
12 months or more	(11,218)	(11,143)
Total	(11,293)	(11,191)
Fair Value
12 months or more	287,336	302,615
Total	287,336	302,615
Unrecognized Losses
12 months or more	(66,759)	(65,210)
Total	(66,759)	(65,210)
Residential mortgage-backed securities
Fair Value
Less than 12 months	244,822	84,023
12 months or more	741,431	765,361
Total	986,253	849,384
Unrealized Losses
Less than 12 months	(2,558)	(708)
12 months or more	(130,193)	(128,559)
Total	(132,751)	(129,267)
Fair Value
12 months or more	313,738	323,342
Total	313,738	323,342
Unrecognized Losses
12 months or more	(57,707)	(55,218)
Total	(57,707)	(55,218)
Corporate debt securities
Fair Value
Less than 12 months	2,440	5,969
12 months or more	26,444	29,097
Total	28,884	35,066
Unrealized Losses
Less than 12 months	(49)	(20)
12 months or more	(1,802)	(1,691)
Total	$ (1,851)	$ (1,711)

DEBT SECURITIES (Tables)

3 Months Ended

Mar. 31, 2026

Investments, Debt and Equity Securities [Abstract]

Schedule of Amortized Cost, Unrealized or Unrecognized Gains and Losses and Fair Values of Securities Classified Available for Sale and Held to Maturity

The tables below provide the amortized cost, unrealized or unrecognized gains and losses, and fair values of debt securities, summarized by major category:


	As of March 31, 2026
(dollars in thousands)	Amortized Cost		Unrealized				Fair Value
			Gross Gains		Gross Losses
Debt securities available for sale1

Obligations of U.S. government corporations and agencies	$	109,005	$	245	$	(244)	$	109,006
Obligations of states and political subdivisions	271,311		862		(12,119)		260,054
Asset-backed securities	246,728		100		(322)		246,506
Commercial mortgage-backed securities	160,476		272		(11,293)		149,455
Residential mortgage-backed securities	1,537,318		5,104		(132,751)		1,409,671
Corporate debt securities	42,183		243		(1,851)		40,575
Total debt securities available for sale	$	2,367,021	$	6,826	$	(158,580)	$	2,215,267



	Amortized Cost		Unrecognized				Fair Value
			Gross Gains		Gross Losses
Debt securities held to maturity
Commercial mortgage-backed securities	$	354,095	$	—	$	(66,759)	$	287,336
Residential mortgage-backed securities	371,445		—		(57,707)		313,738
Total debt securities held to maturity	$	725,540	$	—	$	(124,466)	$	601,074

___________________________________________

1.This table includes debt securities marked at par, with no gain or loss.


	As of December 31, 2025
(dollars in thousands)	Amortized Cost		Unrealized				Fair Value
			Gross Gains		Gross Losses
Debt securities available for sale1

Obligations of U.S. government corporations and agencies	$	111,876	$	250	$	(80)	$	112,046
Obligations of states and political subdivisions	270,682		3,089		(9,898)		263,873
Asset-backed securities	265,203		412		(35)		265,580
Commercial mortgage-backed securities	143,522		611		(11,191)		132,942
Residential mortgage-backed securities	1,464,347		9,336		(129,267)		1,344,416
Corporate debt securities	45,215		187		(1,711)		43,691
Total debt securities available for sale	$	2,300,845	$	13,885	$	(152,182)	$	2,162,548



	Amortized Cost		Unrecognized				Fair Value
			Gross Gains		Gross Losses
Debt securities held to maturity
Commercial mortgage-backed securities	$	367,825	$	—	$	(65,210)	$	302,615
Residential mortgage-backed securities	378,560		—		(55,218)		323,342
Total debt securities held to maturity	$	746,385	$	—	$	(120,428)	$	625,957

___________________________________________

1.This table includes debt securities marked at par, with no gain or loss.

Schedule of Maturities of Debt Securities

All mortgage-backed securities were issued by U.S. government corporations and agencies.


	As of March 31, 2026
(dollars in thousands)	Amortized Cost		Fair Value
Debt securities available for sale
Due in one year or less	$	8,084	$	8,061
Due after one year through five years	85,282		82,185
Due after five years through ten years	351,875		335,172
Due after ten years	1,921,780		1,789,849
Debt securities available for sale	$	2,367,021	$	2,215,267

Debt securities held to maturity
Due in one year or less	$	9,946	$	9,906
Due after one year through five years	35,678		34,363

Due after ten years	679,916		556,805
Debt securities held to maturity	$	725,540	$	601,074

Schedule of Gains and Losses on Debt Securities Available for Sale

Realized gains and losses related to sales and calls of debt securities available for sale are summarized as follows:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Realized gains and losses on debt securities
Gross gains on debt securities		$	24	$	8
Gross losses on debt securities1		(1)		(15,545)
Realized net gains (losses) on debt securities		$	23	$	(15,537)

___________________________________________

1.During the first quarter of 2025, Busey sold available for sale debt securities with a book value of approximately $205.6 million for a pre-tax loss of $15.5 million and related estimated tax benefit of $4.3 million, as part of a balance sheet repositioning strategy.

Schedule of Debt Securities in an Unrealized or Unrecognized Loss Position

The following information pertains to debt securities with gross unrealized or unrecognized losses, aggregated by investment category and the length of time that individual securities have been in a continuous loss position:


	As of March 31, 2026
	Less than 12 months				12 months or more				Total
(dollars in thousands)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Debt securities available for sale

Obligations of U.S. government corporations and agencies1	$	58,527	$	(244)	$	31	$	—	$	58,558	$	(244)
Obligations of states and political subdivisions	97,227		(2,076)		97,076		(10,043)		194,303		(12,119)
Asset-backed securities	83,728		(322)		—		—		83,728		(322)
Commercial mortgage-backed securities	6,505		(75)		71,215		(11,218)		77,720		(11,293)
Residential mortgage-backed securities	244,822		(2,558)		741,431		(130,193)		986,253		(132,751)
Corporate debt securities	2,440		(49)		26,444		(1,802)		28,884		(1,851)
Debt securities available for sale with gross unrealized losses	$	493,249	$	(5,324)	$	936,197	$	(153,256)	$	1,429,446	$	(158,580)




	Fair Value		Unrecognized Losses		Fair Value		Unrecognized Losses
Debt securities held to maturity
Commercial mortgage-backed securities	$	287,336	$	(66,759)	$	287,336	$	(66,759)
Residential mortgage-backed securities	313,738		(57,707)		313,738		(57,707)
Debt securities held to maturity with gross unrecognized losses	$	601,074	$	(124,466)	$	601,074	$	(124,466)

___________________________________________

1.Losses on securities in a continuous loss position for 12 months or more were immaterial, rounding to zero thousand.


	As of December 31, 2025
	Less than 12 months				12 months or more				Total
(dollars in thousands)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Debt securities available for sale

Obligations of U.S. government corporations and agencies	$	39,156	$	(80)	$	—	$	—	$	39,156	$	(80)
Obligations of states and political subdivisions	28,592		(361)		92,205		(9,537)		120,797		(9,898)
Asset-backed securities	10,005		(35)		—		—		10,005		(35)
Commercial mortgage-backed securities	4,986		(48)		71,830		(11,143)		76,816		(11,191)
Residential mortgage-backed securities	84,023		(708)		765,361		(128,559)		849,384		(129,267)
Corporate debt securities	5,969		(20)		29,097		(1,691)		35,066		(1,711)
Debt securities available for sale with gross unrealized losses	$	172,731	$	(1,252)	$	958,493	$	(150,930)	$	1,131,224	$	(152,182)




	Fair Value		Unrecognized Losses		Fair Value		Unrecognized Losses
Debt securities held to maturity
Commercial mortgage-backed securities	$	302,615	$	(65,210)	$	302,615	$	(65,210)
Residential mortgage-backed securities	323,342		(55,218)		323,342		(55,218)
Debt securities held to maturity with gross unrecognized losses	$	625,957	$	(120,428)	$	625,957	$	(120,428)

Additional information about debt securities in an unrealized or unrecognized loss position is presented in the tables below:


	As of March 31, 2026
(dollars in thousands)	Available for Sale			Held to Maturity			Total
Debt securities with gross unrealized or unrecognized losses, fair value	$	1,429,446		$	601,074		$	2,030,520
Gross unrealized or unrecognized losses on debt securities	158,580			124,466			283,046
Ratio of gross unrealized or unrecognized losses to debt securities with gross unrealized or unrecognized losses	11.1		%	20.7		%	13.9		%

Count of debt securities	637			52			689
Count of debt securities in an unrealized or unrecognized loss position	455			52			507


	As of December 31, 2025
(dollars in thousands)	Available for Sale			Held to Maturity			Total
Debt securities with gross unrealized or unrecognized losses, fair value	$	1,131,224		$	625,957		$	1,757,181
Gross unrealized or unrecognized losses on debt securities	152,182			120,428			272,610
Ratio of gross unrealized or unrecognized losses to debt securities with gross unrealized or unrecognized losses	13.5		%	19.2		%	15.5		%

Count of debt securities	637			52			689
Count of debt securities in an unrealized or unrecognized loss position	376			52			428

PORTFOLIO LOANS - Schedule of Current Year Risk Grades of Portfolio Loans, Further Sorted by Origination (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2026	Dec. 31, 2025
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	$ 862,458	$ 2,775,707
2025	2,479,439	1,552,638
2024	1,426,704	1,762,494
2023	1,608,732	2,087,139
2022	1,939,138	1,612,675
Prior	2,615,912	1,277,588
Revolving Loans	2,527,507	2,499,558
Total	13,459,890	13,567,799
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2026, charge-off	292	7,674
2025, charge-off	104	14,536
2024, charge-off	0	4,617
2023, charge-off	267	1,497
2022, charge-off	6,180	13,844
Prior, charge-off	743	11,581
Revolving Loans, charge-off	254	5,893
Total, gross write-offs	7,840	59,642
Commercial loans
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	10,743,286	10,818,515
Commercial loans \| C&I and other commercial
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	203,555	886,826
2025	768,638	582,244
2024	544,736	476,569
2023	401,969	297,050
2022	266,469	243,208
Prior	317,293	148,697
Revolving Loans	1,622,077	1,594,614
Total	4,124,737	4,229,208
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2026, charge-off	50	4,667
2025, charge-off	104	3,332
2024, charge-off	0	4,347
2023, charge-off	257	1,450
2022, charge-off	6,180	13,591
Prior, charge-off	743	11,456
Revolving Loans, charge-off	171	5,716
Total, gross write-offs	7,505	44,559
Commercial loans \| C&I and other commercial \| Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	176,684	833,539
2025	703,182	486,278
2024	444,948	342,560
2023	281,266	207,053
2022	190,104	178,429
Prior	247,451	122,904
Revolving Loans	1,356,182	1,396,826
Total	3,399,817	3,567,589
Commercial loans \| C&I and other commercial \| Watch
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	5,980	21,750
2025	37,677	79,853
2024	79,414	56,387
2023	54,522	38,786
2022	30,451	48,624
Prior	48,220	16,778
Revolving Loans	164,690	112,935
Total	420,954	375,113
Commercial loans \| C&I and other commercial \| Special Mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	6,657	21,712
2025	18,453	11,609
2024	12,256	56,578
2023	19,335	26,343
2022	21,324	5,339
Prior	6,427	800
Revolving Loans	61,112	54,433
Total	145,564	176,814
Commercial loans \| C&I and other commercial \| Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	14,231	8,336
2025	4,942	605
2024	4,800	20,444
2023	45,663	14,603
2022	20,228	9,868
Prior	9,753	3,655
Revolving Loans	27,108	17,883
Total	126,725	75,394
Commercial loans \| C&I and other commercial \| Substandard Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	3	1,489
2025	4,384	3,899
2024	3,318	600
2023	1,183	10,265
2022	4,362	948
Prior	5,442	4,560
Revolving Loans	12,985	12,537
Total	31,677	34,298
Commercial loans \| CRE and Retail real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	496,155	1,339,978
2025	1,158,719	569,197
2024	507,028	841,829
2023	823,939	1,197,182
2022	1,094,074	941,492
Prior	1,437,307	612,815
Revolving Loans	48,822	47,525
Total	5,566,044	5,550,018
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2026, charge-off	0	1,297
2025, charge-off	0	11,057
2024, charge-off	0	0
2023, charge-off	0	0
2022, charge-off	0	253
Prior, charge-off	0	0
Revolving Loans, charge-off	0	0
Total, gross write-offs	0	12,607
Commercial loans \| CRE and Retail real estate \| Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	374,592	1,077,169
2025	970,541	483,950
2024	445,815	710,448
2023	660,590	1,035,426
2022	934,154	740,680
Prior	1,183,257	515,631
Revolving Loans	45,082	43,830
Total	4,614,031	4,607,134
Commercial loans \| CRE and Retail real estate \| Watch
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	100,410	210,673
2025	131,248	61,926
2024	55,151	119,986
2023	126,753	143,072
2022	139,092	161,387
Prior	193,822	69,789
Revolving Loans	2,794	2,572
Total	749,270	769,405
Commercial loans \| CRE and Retail real estate \| Special Mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	19,919	49,648
2025	54,289	22,642
2024	5,388	2,991
2023	27,987	13,811
2022	16,485	32,109
Prior	44,198	18,858
Revolving Loans	731	908
Total	168,997	140,967
Commercial loans \| CRE and Retail real estate \| Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	1,234	2,416
2025	2,122	679
2024	421	3,857
2023	3,243	4,873
2022	3,860	7,316
Prior	12,184	5,324
Revolving Loans	215	215
Total	23,279	24,680
Commercial loans \| CRE and Retail real estate \| Substandard Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	0	72
2025	519	0
2024	253	4,547
2023	5,366	0
2022	483	0
Prior	3,846	3,213
Revolving Loans	0	0
Total	10,467	7,832
Commercial loans \| Real estate construction
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	115,960	447,571
2025	405,560	270,502
2024	251,507	111,929
2023	71,932	112,234
2022	111,876	12,862
Prior	14,866	2,733
Revolving Loans	80,804	81,458
Total	1,052,505	1,039,289
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2026, charge-off	0	0
2025, charge-off	0	0
2024, charge-off	0	0
2023, charge-off	0	0
2022, charge-off	0	0
Prior, charge-off	0	0
Revolving Loans, charge-off	0	0
Total, gross write-offs	0	0
Commercial loans \| Real estate construction \| Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	102,064	395,019
2025	373,586	268,117
2024	251,234	107,930
2023	69,954	89,673
2022	69,315	5,356
Prior	7,516	2,733
Revolving Loans	74,606	74,237
Total	948,275	943,065
Commercial loans \| Real estate construction \| Watch
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	13,896	18,571
2025	2,153	2,112
2024	0	3,999
2023	1,978	22,561
2022	42,561	167
Prior	160	0
Revolving Loans	6,198	7,221
Total	66,946	54,631
Commercial loans \| Real estate construction \| Special Mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	0	17,961
2025	18,945	0
2024	0	0
2023	0	0
2022	0	6,573
Prior	6,434	0
Revolving Loans	0	0
Total	25,379	24,534
Commercial loans \| Real estate construction \| Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	0	16,020
2025	10,876	0
2024	0	0
2023	0	0
2022	0	766
Prior	756	0
Revolving Loans	0	0
Total	11,632	16,786
Commercial loans \| Real estate construction \| Substandard Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	0	0
2025	0	273
2024	273	0
2023	0	0
2022	0	0
Prior	0	0
Revolving Loans	0	0
Total	273	273
Retail loans
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	2,716,604	2,749,284
Retail loans \| CRE and Retail real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	46,038	96,099
2025	141,672	128,430
2024	121,544	298,742
2023	281,637	450,218
2022	439,711	410,552
Prior	841,201	512,458
Revolving Loans	247,818	258,117
Total	2,119,621	2,154,616
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2026, charge-off	70	1,164
2025, charge-off	0	0
2024, charge-off	0	0
2023, charge-off	0	0
2022, charge-off	0	0
Prior, charge-off	0	51
Revolving Loans, charge-off	81	36
Total, gross write-offs	151	1,251
Retail loans \| CRE and Retail real estate \| Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	45,952	93,212
2025	138,678	127,475
2024	120,634	269,877
2023	252,430	446,309
2022	436,101	407,851
Prior	836,870	508,504
Revolving Loans	246,306	252,987
Total	2,076,971	2,106,215
Retail loans \| CRE and Retail real estate \| Watch
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	86	2,686
2025	2,590	569
2024	530	24,601
2023	24,972	1,492
2022	1,464	267
Prior	512	482
Revolving Loans	545	577
Total	30,699	30,674
Retail loans \| CRE and Retail real estate \| Special Mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	0	47
2025	47	78
2024	72	4,028
2023	0	1,454
2022	1,432	1,686
Prior	1,661	0
Revolving Loans	207	214
Total	3,419	7,507
Retail loans \| CRE and Retail real estate \| Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	0	0
2025	0	0
2024	0	108
2023	4,108	440
2022	135	484
Prior	1,100	631
Revolving Loans	0	136
Total	5,343	1,799
Retail loans \| CRE and Retail real estate \| Substandard Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	0	154
2025	357	308
2024	308	128
2023	127	523
2022	579	264
Prior	1,058	2,841
Revolving Loans	760	4,203
Total	3,189	8,421
Retail loans \| Retail other
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	750	5,233
2025	4,850	2,265
2024	1,889	33,425
2023	29,255	30,455
2022	27,008	4,561
Prior	5,245	885
Revolving Loans	527,986	517,844
Total	596,983	594,668
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2026, charge-off	172	546
2025, charge-off	0	147
2024, charge-off	0	270
2023, charge-off	10	47
2022, charge-off	0	0
Prior, charge-off	0	74
Revolving Loans, charge-off	2	141
Total, gross write-offs	184	1,225
Retail loans \| Retail other \| Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	750	5,233
2025	4,850	2,265
2024	1,889	33,349
2023	29,179	30,321
2022	26,892	4,561
Prior	5,245	885
Revolving Loans	527,985	517,680
Total	596,790	594,294
Retail loans \| Retail other \| Substandard Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2026	0	0
2025	0	0
2024	0	76
2023	76	134
2022	116	0
Prior	0	0
Revolving Loans	1	164
Total	$ 193	$ 374

STOCK-BASED COMPENSATION (Tables)

3 Months Ended

Mar. 31, 2026

Share-Based Payment Arrangement [Abstract]

Schedule of Changes in Busey’s Outstanding Equity Awards

Changes in Busey’s outstanding equity awards are presented in the tables below:


	RSU Awards	PSU Awards1	DSU Awards
Nonvested at December 31, 2025	1,320,537	525,501	41,218
Granted	—	—	—
Dividend equivalents earned	13,929	1,877	435
Vested	(613,166)	(43,283)	(41,653)
Forfeited	(58,395)	(32,086)	—
Nonvested at March 31, 2026	662,905	452,009	—

Vested and outstanding at March 31, 2026	—	—	189,269

___________________________________________

1.Represents target shares at the grant date.


	Options	SSARs
Outstanding at December 31, 2025	15,106	270,398
Exercised	(5,280)	(134,103)
Forfeited	—	—
Expired	—	—
Outstanding at March 31, 2026	9,826	136,295

Exercisable at March 31, 2026	9,826	119,457

Schedule of Shares Remaining Available for Issuance Under Busey’s Equity Compensation Plans

Shares remaining available for issuance under Busey’s equity compensation plans as of March 31, 2026, are set forth in the table below:


Plan						Shares Remaining Available for Issuance Pursuant to the Plan
2020 Equity Plan						746,172
ESPP						254,688

Schedule of Stock-Based Compensation Expense

Busey recognized compensation expense related to non-vested equity awards as summarized in the table below:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Stock-based compensation expense
Salaries, wages, and employee benefits1		$	3,930	$	3,217
Other expense2		206		177
Total stock-based compensation expense		$	4,136	$	3,394

___________________________________________

1.Includes expenses for RSUs, PSUs, SSARs, and the ESPP.

2.Represents expenses for DSU awards.

Schedule of Unamortized Stock-Based Compensation Expense

Unamortized compensation expense related to non-vested equity awards is summarized in the table below:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025





Unamortized stock-based compensation	$	9,873	$	15,309

Weighted average period over which expense is to be recognized on awards issued under Busey's 2020 Equity Plan	1.9 years		1.8 years
Weighted average period over which expense is to be recognized on CrossFirst replacement awards	1.1 years		1.2 years

DERIVATIVE FINANCIAL INSTRUMENTS - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Cash pledged to secure obligations under derivative contracts \| Not Designated as Hedging Instrument
Derivative [Line Items]
Variable rate, commercial loans that are supported by the interest rate swap contracts	$ 1,270,000	$ 1,160,000
Cash pledged to secure obligations under derivative contracts \| Cash Flow Hedging \| Designated as Hedging Instrument
Derivative [Line Items]
Notional amount	700,000	500,000
Prime Loan Swap \| Designated as Hedging Instrument
Derivative [Line Items]
Notional amount	300,000
Prime Loan Swap \| Cash Flow Hedging
Derivative [Line Items]
Notional amount	300,000	300,000
SOFR Loan Swaps \| Designated as Hedging Instrument
Derivative [Line Items]
Notional amount	400,000
SOFR Loan Swaps \| Cash Flow Hedging
Derivative [Line Items]
Notional amount	$ 400,000	$ 200,000

CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Interest income
Interest and fees on loans	$ 200,555	$ 139,533
Taxable interest income	21,095	18,297
Non-taxable interest income	1,733	642
Dividend income on bank stock	880	759
Other interest income	1,222	7,584
Total interest income	225,485	166,815
Interest expense
Deposits	66,026	57,312
Federal funds purchased and securities sold under agreements to repurchase	896	876
Short-term borrowings	911	67
Long-term borrowings	1,068	287
Subordinated notes	1,353	3,187
Junior subordinated debt owed to unconsolidated trusts	1,262	1,355
Total interest expense	71,516	63,084
Net interest income	153,969	103,731
Provision for credit losses	3,058	45,593
Net interest income after provision for credit losses	150,911	58,138
Noninterest income
Mortgage revenue	438	329
Income on bank owned life insurance	1,616	1,446
Realized net gains (losses) on securities	23	(15,537)
Unrealized net gains (losses) recognized on equity securities	(963)	(231)
Other noninterest income	5,726	4,520
Total noninterest income	42,265	21,223
Noninterest expense
Salaries, wages, and employee benefits	85,230	67,563
Data processing	9,864	9,575
Net occupancy expense of premises	7,652	5,799
Furniture and equipment expenses	2,177	1,744
Professional fees	3,239	9,511
Amortization of intangible assets	4,291	3,083
Interchange expense	1,116	1,343
FDIC insurance	2,451	2,167
Other noninterest expense	13,499	11,245
Total noninterest expense	129,519	112,030
Income (loss) before income taxes	63,657	(32,669)
Income taxes	13,676	(2,679)
Net income (loss)	49,981	(29,990)
Dividends on preferred stock	4,589	0
Net income (loss) available to common stockholders	$ 45,392	$ (29,990)
Weighted average number of common shares outstanding
Weighted average number of common shares outstanding, basic (in shares)	86,692,001	68,517,647
Weighted average number of common shares outstanding, diluted (in shares)	87,831,295	68,517,647
Basic earnings (loss) per common share (in dollars per share)	$ 0.52	$ (0.44)
Diluted earnings (loss) per common share (in dollars per share)	$ 0.52	$ (0.44)
Wealth management fees
Noninterest income
Noninterest income	$ 19,370	$ 17,364
Payment technology solutions
Noninterest income
Noninterest income	5,077	5,073
Treasury management services
Noninterest income
Noninterest income	4,826	3,017
Card services and ATM fees
Noninterest income
Noninterest income	4,646	3,709
Other service charges on deposit accounts
Noninterest income
Noninterest income	$ 1,506	$ 1,533

PORTFOLIO LOANS - Schedule of Distribution of Portfolio Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total portfolio loans	$ 13,459,890	$ 13,567,799
ACL	(169,054)	(174,023)	$ (195,210)	$ (83,404)
Portfolio loans, net	13,290,836	13,393,776
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total portfolio loans	10,743,286	10,818,515
Commercial loans \| C&I and other commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total portfolio loans	4,124,737	4,229,208
ACL	(57,804)	(61,370)	(89,304)	(21,589)
Commercial loans \| CRE and Retail real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total portfolio loans	5,566,044	5,550,018
ACL	(70,100)	(70,328)	(68,478)	(32,301)
Commercial loans \| Real estate construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total portfolio loans	1,052,505	1,039,289
ACL	(12,588)	(11,568)	(8,689)	(3,345)
Retail loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total portfolio loans	2,716,604	2,749,284
Retail loans \| CRE and Retail real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total portfolio loans	2,119,621	2,154,616
ACL	(27,140)	(29,178)	(26,399)	(23,711)
Retail loans \| Retail other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total portfolio loans	596,983	594,668
ACL	$ (1,422)	$ (1,579)	$ (2,340)	$ (2,458)

BORROWINGS

3 Months Ended

Mar. 31, 2026

Debt Disclosure [Abstract]

BORROWINGS

NOTE 7. BORROWINGS

Securities Sold Under Agreements to Repurchase

Securities sold under agreements to repurchase, which are classified as secured borrowings, generally mature daily. Securities sold under agreements to repurchase are reflected at the amount of cash received in connection with the transaction. The underlying securities are held by Busey’s safekeeping agent. Busey may be required to provide additional collateral based on fluctuations in the fair value of the underlying securities. Securities sold under agreements to repurchase were as follows:


	As of
(dollars in thousands)	March 31, 2026			December 31, 2025
Securities sold under agreements to repurchase	$	156,364		$	166,929
Weighted average rate for securities sold under agreements to repurchase	2.40		%	2.22		%

Revolving Line of Credit

Pursuant to the Second Amended and Restated Credit Agreement, on March 31, 2026, Busey had access to a $40.0 million revolving line of credit bearing an interest rate of 1.80% plus the one-month forward-looking term rate based on SOFR. Effective April 30, 2026, Busey executed an amendment to its Second Amended and Restated Credit Agreement, pursuant to which: (1) Busey’s revolving line of credit increased to $50.0 million, (2) the interest rate on the revolving line of credit was reduced to the one-month Term SOFR rate plus 1.65%, and (3) the termination date for the agreement was extended to April 30, 2027.

As of March 31, 2026, there was no balance outstanding on the revolving line of credit. The revolving line of credit incurs an insignificant non-usage fee based on any undrawn amounts.

Short-term Borrowings

Busey’s short-term borrowings include, as applicable, loans maturing within one year of the loan origination date, the current portion of long-term debt that is due within 12 months, and federal funds purchased. Federal funds purchased are short-term borrowings that generally mature between one day and 90 days. During the first quarter of 2026, Busey purchased federal funds to test operational availability to access funds if needed.

Short-term borrowings are presented in the table below:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Short-term borrowings

FHLB advances maturing in less than one year from date of origination, and the current portion of long-term FHLB advances due within 12 months	$	170,000	$	—


Total short-term borrowings	$	170,000	$	—

Funds borrowed from the FHLB, listed above, consisted of two notes with a weighted average interest rate of 3.80% and a weighted average maturity period of 1 day as of March 31, 2026.

Long-term Borrowings

Busey’s long-term borrowings consist of borrowings maturing more than one year from the loan origination date, excluding the current portion that is due within 12 months, and finance lease liabilities. Long-term borrowings are presented in the table below:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Long-term borrowings
FHLB borrowings	$	114,078	$	102,792
Secured borrowings	3,211		4,791

Finance lease liabilities	6,178		6,223
Total long-term borrowings	$	123,467	$	113,806

Funds borrowed from the FHLB, listed above, consisted of seventeen notes with a weighted average interest rate of 2.49% and a weighted average maturity period of 1.70 years as of March 31, 2026. Maturity dates for the long-term FHLB borrowings range from May 2027 through December 2030. In comparison, as of December 31, 2025, funds borrowed from the FHLB, listed above, consisted of fifteen notes with a weighted average interest rate of 2.43% and a weighted average maturity period of 1.96 years.

Acquired SBA loans that did not qualify for sale accounting treatment are presented as secured borrowings. Secured borrowings consisted of six notes with a weighted average maturity period of 15.37 years as of March 31, 2026. Maturity dates for the secured borrowings range from September 2030 through September 2045. In comparison, as of December 31, 2025, secured borrowings consisted of seven notes with a weighted average maturity period of 17.01 years.

Subordinated Notes

On June 2, 2022, Busey issued $100.0 million aggregate principal amount of 5.000% fixed-to-floating rate subordinated notes maturing June 15, 2032, which qualify as Tier 2 capital for regulatory purposes. The price to the public for the subordinated notes was 100% of the principal amount of the subordinated notes. Interest on the subordinated notes accrues at a rate equal to (1) 5.000% per annum from the original issue date to, but excluding, June 15, 2027, payable semiannually in arrears, and (2) a floating rate per annum equal to a benchmark rate, which is the Three-Month Term SOFR (as defined in the subordinated notes), plus a spread of 252 bps from and including June 15, 2027, payable quarterly in arrears. The subordinated notes have an optional redemption, in whole or in part, on any interest payment date on or after June 15, 2027.

Unamortized debt issuance costs related to Busey’s subordinated notes are presented in the following table:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025



Unamortized debt issuance costs	$	501	$	605

Junior Subordinated Debt Owed to Unconsolidated Trusts

In January 2026, Busey’s Board of Directors approved the redemption of the trust preferred securities issued by First Busey Statutory Trust II. Approval for the redemption has been received from the Federal Reserve Bank. Busey expects to complete the redemption in June of 2026.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
SIGNIFICANT ACCOUNTING POLICIES (Policies)	Mar. 31, 2026
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations First Busey Corporation, a Nevada corporation organized in 1980, is an $18.04 billion financial holding company headquartered in Leawood, Kansas. Busey’s stock is traded on The Nasdaq Global Select Market, with its common stock trading under the symbol “BUSE” and its depositary shares of Busey Series B Preferred Stock trading under the symbol “BUSEP.” Busey operates and reports its business in three segments: Banking, Wealth Management, and FirsTech. •The Banking operating segment provides a full range of banking services to individual and corporate customers through its banking center network in Arizona, Colorado, Florida, Illinois, Indiana, Kansas, Missouri, New Mexico, Oklahoma, and Texas. •The Wealth Management operating segment provides a full range of asset management, investment, brokerage, fiduciary, philanthropic advisory, tax preparation, and farm management services to individuals, businesses, and foundations. •The FirsTech operating segment provides comprehensive and innovative payment technology solutions including online, mobile, and voice-recognition bill payments; money management and credit card networks; direct debit services; lockbox remittance processing for payments made by mail; and walk-in payments. FirsTech also provides additional tools to help clients with billing, reconciliation, bill reminders, and treasury services. For additional information about Busey's operating segments, see “Note 16. Operating Segments and Related Information.” Busey conducts its Banking and Wealth Management services through Busey Bank, and provides payment technology solutions through Busey Bank’s wholly owned subsidiary, FirsTech. Busey also has various other subsidiaries that are not significant to the consolidated entity.
Basis of Financial Statement Presentation	Basis of Financial Statement Presentation These unaudited consolidated financial statements and related notes should be read together with the audited consolidated financial statements included in Busey's 2025 Annual Report. These interim unaudited consolidated financial statements serve to update Busey’s 2025 Annual Report and may not include all information and notes necessary to constitute a complete set of financial statements. Busey’s unaudited consolidated financial statements are prepared in conformity with GAAP, and reflect the elimination of intercompany accounts and transactions. Certain prior year amounts have been reclassified to conform to the current period presentation. These reclassifications did not have a material impact on Busey’s consolidated financial condition or results of operations. In the opinion of Busey’s management, the unaudited consolidated financial statements reflect all normal, recurring adjustments needed to present fairly Busey’s results for the interim periods. The results of operations for interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period.
Use of Estimates	Use of Estimates In preparing the accompanying unaudited consolidated financial statements in conformity with GAAP, Busey’s management is required to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and the disclosures provided. Actual results could differ from those estimates. Critical accounting estimates which are particularly susceptible to significant change relate to the fair value of assets acquired and liabilities assumed in business combinations, goodwill, income taxes, and the determination of the ACL.
Trust Assets	Trust Assets Assets held for customers in a fiduciary or agency capacity, other than trust cash on deposit at Busey Bank, are not Busey’s assets and, accordingly, are not included in the accompanying unaudited consolidated financial statements.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include cash on hand, cash items in process of collection, amounts due from other banks, and interest-bearing deposits held with other financial institutions with original maturities of three months or less. The carrying amount of these instruments is considered a reasonable estimate of fair value.
Interest- Bearing Time Deposits in Other Banks	Interest-bearing time deposits in other banks consist of certificates of deposit with original maturities greater than three months and are carried at amortized cost.
Income Taxes	Income Taxes Busey is subject to income taxes in U.S. federal and various state jurisdictions. First Busey Corporation and its subsidiaries file consolidated federal and state income tax returns with each subsidiary computing its taxes on a separate entity basis. Tax regulations within each jurisdiction are subject to the interpretation of the related tax laws and regulations, which requires significant judgment. Busey monitors evolving federal and state tax legislation and its potential impact on operations on an ongoing basis. As of March 31, 2026, Busey remains under examination by the Illinois Department of Revenue for M&M's tax filings for the tax years ended December 31, 2022 and 2023.
Impact of Recently Adopted Accounting Standards and Recently Issued Accounting Standards Not Yet Adopted	Impact of Recently Adopted Accounting Standards In July 2025, the FASB issued ASU 2025-05 “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets,” providing a practical expedient which, if elected, permits an entity to assume that current conditions as of the balance sheet date will remain static for the remaining life of the assets, removing the requirement to consider reasonable, supportable forecasts. This ASU was adopted prospectively for annual and interim reporting periods beginning January 1, 2026. Adoption of this standard did not have a material impact on Busey’s financial position or results of operations. In November 2024, the FASB issued ASU 2024-04 “Debt—Debt with Conversion and Other Options (Subtopic 470-20): Induced Conversions of Convertible Debt Instruments” to clarify when certain settlements of convertible debt instruments should be accounted for as an induced conversion. This ASU was adopted on a prospective basis for annual and interim reporting periods beginning January 1, 2026. Because Busey does not currently have any convertible debt, adoption of this standard did not have a material impact on Busey’s financial position or results of operations. Recently Issued Accounting Standards Not Yet Adopted In November 2025, the FASB issued ASU 2025-09 “Derivatives and Hedging (Topic 815): Hedge Accounting Improvements” to expand the hedged risks permitted to be aggregated in a group of individual forecasted transactions, enabling entities to apply hedge accounting treatment to a broader portfolio of forecasted transactions. Under the amendments in this update, a group of individual forecasted transactions can be designated as a cash flow hedge if they have a similar risk exposure. Individual forecasted transactions are considered to have a similar risk exposure when the derivative used as the hedging instrument is highly effective against each hedged risk in the group. This update is to be applied on a prospective basis for all hedging relationships; there is an option to elect to adopt the amendments in this update for hedging relationships that exist as of the date of adoption. This update will be effective for Busey for annual and interim reporting periods beginning January 1, 2027. Early adoption is permitted. Busey is currently evaluating the effect this ASU may have on its financial position and results of operations. In September 2025, the FASB issued ASU 2025-07 “Derivatives and Hedging (Topic 815) and Revenue from Contracts with Customers (Topic 606): Derivatives Scope Refinements and Scope Clarification for Share-Based Noncash Consideration from a Customer in a Revenue Contract,” to reduce diversity in the application of derivative accounting practices. This update provides a scope limitation on the definition of a derivative subject to derivative accounting under ASC Topic 815, Derivatives and Hedging, to exclude certain non-exchange-traded contracts with contingencies based on operations or activities specific to one of the parties to the contract. In addition, this update clarifies that share-based noncash consideration from a customer that is contingent on the satisfaction of performance obligations should not be recognized at contract inception as a derivative asset or an equity security, but rather should be accounted for under the guidance in ASC Topic 606, Revenue from Contracts with Customers, and that guidance in other topics does not apply to share-based noncash consideration from a customer for the transfer of goods or services unless or until the entity’s right to receive or retain the share-based noncash consideration is unconditional under ASC Topic 606. The amendments in this update may be applied on either a prospective or modified retrospective basis, and will be effective for Busey for annual and interim reporting periods beginning January 1, 2027. Early adoption is permitted. Busey is currently evaluating the effect this ASU may have on its financial position and results of operations. In September 2025, the FASB issued ASU 2025-06 “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software,” changing the criteria for capitalizing software costs to the following: (1) a commitment has been made to fund the software project, and (2) it is probable the project will be completed and used to perform its intended function. Under this update, software development stages are no longer a consideration in the determination of which costs are capitalized. The amendments in this update may be adopted on a prospective, modified transition, or retrospective basis, and will be effective for Busey for annual and interim reporting periods beginning January 1, 2028. Early adoption is permitted. Busey is currently evaluating the effect this ASU may have on its financial position and results of operations. In November 2024, the FASB issued ASU 2024-03 “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses” to require additional disclosures within the notes to the financial statements about certain expense items. Specifically, disaggregation of income statement captions that contain expenses within the following five categories is required: (1) purchases of inventory, (2) employee compensation, (3) depreciation, (4) intangible asset amortization, and (5) depreciation, depletion, and amortization (“DD&A”) costs recognized as part of oil- and gas-producing activities or other amounts of depletion expense. Further, this update requires disclosure of the total amount of selling expenses and the entity’s definition of selling expenses. This update provides a practical expedient for banks and bank holding companies to continue presenting salaries and employee benefits in conformity with SEC Rule 210.9-04 instead of requiring those entities to apply the employee compensation definition included in Subtopic 220-40. The amendments in this update may be applied on either a prospective or retrospective basis and will be effective for Busey beginning with the annual reporting period ending December 31, 2027, and interim reporting periods beginning January 1, 2028. Early adoption is permitted. Because this update relates only to disclosure, Busey does not expect adoption of this ASU to have any impact on its financial position or results of operations. In October 2023, the FASB issued ASU 2023‑06 “Disclosure Improvements: Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative” which aligns certain GAAP disclosure requirements with those of the SEC in order to better facilitate comparisons between SEC registrants and entities that are not subject to SEC reporting requirements. The amendments in this ASU should be applied prospectively, and the effective date will be the date on which the SEC removes the related disclosure from Regulation S‑X or Regulation S‑K. Early adoption is prohibited. If the SEC has not removed the related disclosures by June 30, 2027, the pending content of this update will be removed from the ASC and have no further effect. Because this update relates only to disclosure, Busey does not expect adoption of this ASU to have a material impact on its financial position or results of operations.
Subsequent Events	Subsequent Events Busey has evaluated subsequent events for potential recognition and/or disclosure through the date the unaudited consolidated financial statements included in this Quarterly Report were issued.
Fair Value Measurements	NOTE 13. FAIR VALUE MEASUREMENTS The fair value of an asset or liability is the price that would be received by selling that asset or paid in transferring that liability (exit price) in an orderly transaction occurring in the principal market (or most advantageous market in the absence of a principal market) for such asset or liability. ASC Topic 820 “Fair Value Measurement” establishes a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The fair value hierarchy is as follows: •Level 1 Inputs—Unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. •Level 2 Inputs—Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, volatility, prepayment speeds, credit risks, etc.) or inputs that are derived principally from or corroborated by market data by correlation or other means. •Level 3 Inputs—Unobservable inputs for estimating the fair values of assets or liabilities that reflect the Company’s own assumptions about the assumptions that market participants would use in pricing the assets or liabilities. A description of the valuation methodologies used for instruments measured at fair value, as well as the general classification of such instruments pursuant to the valuation hierarchy, is set forth below. These valuation methodologies were applied to Busey’s assets and liabilities that are carried at fair value. In general, fair value estimates are based upon quoted market prices, when available. If such quoted market prices are not available, fair values are estimated utilizing independent valuation techniques that consider identical or similar securities for which significant assumptions are derived primarily from or corroborated by observable data. Valuation adjustments may be made to ensure that financial instruments are recorded at their estimated fair values. These adjustments may include amounts to reflect, among other things, counterparty credit quality and the company's creditworthiness as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. While management believes Busey's valuation methodologies are appropriate and consistent with other market participants, the use of different methodologies or assumptions to estimate the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date. Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis Debt Securities Available for Sale Debt securities classified as available for sale are reported at fair value, which is estimated using Level 2 inputs. Busey obtains fair value measurements from an independent pricing service. The independent pricing service utilizes evaluated pricing models that vary by asset class and incorporate available trade, bid, and other market information. Because many fixed income securities do not trade on a daily basis, the independent pricing service applies available information to prepare evaluations, with a focus on observable market data such as benchmark curves, benchmarking of like securities, sector groupings, and matrix pricing. The independent pricing service uses model processes, such as the Option Adjusted Spread model, to assess interest rate impact and develop prepayment scenarios. Models and processes take into account market conventions. For each asset class, a team of evaluators gathers information from market sources and integrates relevant credit information, perceived market movements, and sector news into the evaluated pricing applications and models. Market inputs that the independent pricing service normally seeks for evaluations of securities, listed in approximate order of priority, include: benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data including market research publications. The independent pricing service also monitors market indicators, industry, and economic events. For certain security types, additional inputs may be used or some of the market inputs may not be applicable. Evaluators may prioritize inputs differently on any given day for any security based on market conditions, and not all inputs listed are available for use in the evaluation process for each security evaluation on a given day. Because the data utilized was observable, the securities have been classified as Level 2. Equity Securities Equity securities are reported at fair value, which is estimated using Level 1 or Level 2 inputs. Fair value measurements of mutual funds or stock in active markets are estimated using unadjusted quoted prices for identical assets at the measurement date and are classified as Level 1. Fair value measurements of stock that are not active use quoted prices for identical or similar assets in markets and are classified as Level 2. Derivative Assets and Derivative Liabilities Busey’s derivative assets and derivative liabilities are reported at fair value, which is measured using Level 2 or Level 3 inputs. Fair values of derivative assets and liabilities are estimated based on prices that are obtained from a third-party which uses observable market inputs and, with the exception of risk participation agreements, are classified as Level 2. Due to the significance of unobservable inputs, derivative assets and liabilities related to risk participation agreements are classified as Level 3. Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis Certain financial assets and financial liabilities are measured at estimated fair value on a non-recurring basis; that is, the instruments are not measured at estimated fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment). Loans Evaluated Individually Busey does not record portfolio loans at estimated fair value on a recurring basis. However, periodically, a loan is evaluated individually and is reported at the estimated fair value of the underlying collateral, less estimated costs to sell, if repayment is expected solely from the collateral. If the estimated collateral value is not sufficient, a specific reserve is recorded. Collateral values are estimated using a combination of observable inputs, including recent appraisals, and unobservable inputs based on customized discounting criteria. Due to the significance of unobservable inputs, fair values of individually evaluated collateral dependent loans have been classified as Level 3. OREO and Other Repossessed Assets Non-financial assets measured at fair value, upon initial recognition or subsequent impairment, include OREO and other repossessed assets. OREO properties and other repossessed assets are measured using a combination of observable inputs, including recent appraisals, and unobservable inputs. Due to the significance of unobservable inputs, the estimated fair values of all OREO and other repossessed assets have been classified as Level 3. Bank Property Held for Sale Bank property held for sale represents certain banking center office buildings which Busey has closed and consolidated with other existing banking centers. Bank property held for sale is measured at the lower of amortized cost or estimated fair value less estimated costs to sell. Fair value estimates were based upon discounted appraisals or real estate listing prices. Due to the significance of unobservable inputs, estimated fair values of all bank property held for sale have been classified as Level 3. Bank property held for sale is included in premises and equipment, net on Busey’s Consolidated Balance Sheets (Unaudited).

EARNINGS PER COMMON SHARE - Schedule of Computation of Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Earnings Per Share [Abstract]
Net income (loss)	$ 49,981	$ (29,990)
Dividends on preferred stock	(4,589)	0
Net income (loss) available to common stockholders	$ 45,392	$ (29,990)
Weighted average number of common shares outstanding, basic (in shares)	86,692,001	68,517,647
Dilutive effect of outstanding equity-based awards (in shares)	1,139,294	0
Weighted average number of common shares outstanding, diluted (in shares)	87,831,295	68,517,647
Basic earnings (loss) per common share (in dollars per share)	$ 0.52	$ (0.44)
Diluted earnings (loss) per common share (in dollars per share)	$ 0.52	$ (0.44)
Anti-dilutive equity-based awards (in shares)	0	2,794,422

OPERATING SEGMENTS AND RELATED INFORMATION - Schedule of Financial Results by Operating Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Segment Reporting Information [Line Items]
Interest income	$ 225,485	$ 166,815
Intersegment interest income	0	0
Interest expense	71,516	63,084
Intersegment interest expense	0	0
Net interest income	153,969	103,731
Provision for credit losses	3,058	45,593
Net interest income after provision for credit losses	150,911	58,138
Noninterest income
All other noninterest income	6,840	(9,473)
Intersegment noninterest income	0	0
Total noninterest income	42,265	21,223
Revenue	196,234	124,954
Noninterest expense
Salaries, wages, and employee benefits	85,230	67,563
Data processing	9,864	9,575
Amortization of intangible assets	4,291	3,083
Interchange expense	1,116	1,343
All other noninterest expense	29,018	30,466
Intersegment noninterest expense	0	0
Total noninterest expense	129,519	112,030
Income (loss) before income taxes	63,657	(32,669)
Income taxes	13,676	(2,679)
Net income (loss)	49,981	(29,990)
Wealth management fees
Noninterest income
Noninterest income	19,370	17,364
Payment technology solutions
Noninterest income
Noninterest income	5,077	5,073
Treasury management services
Noninterest income
Noninterest income	4,826	3,017
Card services and ATM fees
Noninterest income
Noninterest income	4,646	3,709
Other service charges on deposit accounts
Noninterest income
Noninterest income	1,506	1,533
Other
Segment Reporting Information [Line Items]
Interest income	78	3
Intersegment interest income	(15)	(13)
Interest expense	2,642	4,567
Intersegment interest expense	(504)	(491)
Net interest income	(2,075)	(4,086)
Provision for credit losses	0	0
Net interest income after provision for credit losses	(2,075)	(4,086)
Noninterest income
All other noninterest income	(938)	(294)
Intersegment noninterest income	(3,394)	(697)
Total noninterest income	(4,332)	(991)
Revenue	(6,407)	(5,077)
Noninterest expense
Salaries, wages, and employee benefits	0	11,325
Data processing	33	96
Amortization of intangible assets	0	0
Interchange expense	0	0
All other noninterest expense	1,808	9,287
Intersegment noninterest expense	(1,969)	(5,814)
Total noninterest expense	(128)	14,894
Income (loss) before income taxes	(6,279)	(19,971)
Income taxes	(1,533)	(3,694)
Net income (loss)	(4,746)	(16,277)
Other \| Wealth management fees
Noninterest income
Noninterest income	0	0
Other \| Payment technology solutions
Noninterest income
Noninterest income	0	0
Other \| Treasury management services
Noninterest income
Noninterest income	0	0
Other \| Card services and ATM fees
Noninterest income
Noninterest income	0	0
Other \| Other service charges on deposit accounts
Noninterest income
Noninterest income	0	0
Banking \| Operating Segments
Segment Reporting Information [Line Items]
Interest income	225,407	166,812
Intersegment interest income	0	0
Interest expense	68,874	58,517
Intersegment interest expense	504	491
Net interest income	156,029	107,804
Provision for credit losses	3,058	45,593
Net interest income after provision for credit losses	152,971	62,211
Noninterest income
All other noninterest income	7,621	(9,379)
Intersegment noninterest income	2,833	352
Total noninterest income	21,432	(768)
Revenue	177,461	107,036
Noninterest expense
Salaries, wages, and employee benefits	71,707	46,726
Data processing	8,182	7,949
Amortization of intangible assets	4,110	2,841
Interchange expense	0	0
All other noninterest expense	25,682	19,825
Intersegment noninterest expense	679	4,665
Total noninterest expense	110,360	82,006
Income (loss) before income taxes	64,043	(20,563)
Income taxes	13,803	(870)
Net income (loss)	50,240	(19,693)
Banking \| Operating Segments \| Wealth management fees
Noninterest income
Noninterest income	0	0
Banking \| Operating Segments \| Payment technology solutions
Noninterest income
Noninterest income	0	0
Banking \| Operating Segments \| Treasury management services
Noninterest income
Noninterest income	4,826	3,017
Banking \| Operating Segments \| Card services and ATM fees
Noninterest income
Noninterest income	4,646	3,709
Banking \| Operating Segments \| Other service charges on deposit accounts
Noninterest income
Noninterest income	1,506	1,533
Wealth Management \| Operating Segments
Segment Reporting Information [Line Items]
Interest income	0	0
Intersegment interest income	0	0
Interest expense	0	0
Intersegment interest expense	0	0
Net interest income	0	0
Provision for credit losses	0	0
Net interest income after provision for credit losses	0	0
Noninterest income
All other noninterest income	157	202
Intersegment noninterest income	0	0
Total noninterest income	19,527	17,566
Revenue	19,527	17,566
Noninterest expense
Salaries, wages, and employee benefits	8,866	7,031
Data processing	763	593
Amortization of intangible assets	181	242
Interchange expense	0	0
All other noninterest expense	852	737
Intersegment noninterest expense	750	780
Total noninterest expense	11,412	9,383
Income (loss) before income taxes	8,115	8,183
Income taxes	1,948	1,964
Net income (loss)	6,167	6,219
Wealth Management \| Operating Segments \| Wealth management fees
Noninterest income
Noninterest income	19,370	17,364
Wealth Management \| Operating Segments \| Payment technology solutions
Noninterest income
Noninterest income	0	0
Wealth Management \| Operating Segments \| Treasury management services
Noninterest income
Noninterest income	0	0
Wealth Management \| Operating Segments \| Card services and ATM fees
Noninterest income
Noninterest income	0	0
Wealth Management \| Operating Segments \| Other service charges on deposit accounts
Noninterest income
Noninterest income	0	0
FirsTech \| Operating Segments
Segment Reporting Information [Line Items]
Interest income	0	0
Intersegment interest income	15	13
Interest expense	0	0
Intersegment interest expense	0	0
Net interest income	15	13
Provision for credit losses	0	0
Net interest income after provision for credit losses	15	13
Noninterest income
All other noninterest income	0	(2)
Intersegment noninterest income	561	345
Total noninterest income	5,638	5,416
Revenue	5,653	5,429
Noninterest expense
Salaries, wages, and employee benefits	4,657	2,481
Data processing	886	937
Amortization of intangible assets	0	0
Interchange expense	1,116	1,343
All other noninterest expense	676	617
Intersegment noninterest expense	540	369
Total noninterest expense	7,875	5,747
Income (loss) before income taxes	(2,222)	(318)
Income taxes	(542)	(79)
Net income (loss)	(1,680)	(239)
FirsTech \| Operating Segments \| Wealth management fees
Noninterest income
Noninterest income	0	0
FirsTech \| Operating Segments \| Payment technology solutions
Noninterest income
Noninterest income	5,077	5,073
FirsTech \| Operating Segments \| Treasury management services
Noninterest income
Noninterest income	0	0
FirsTech \| Operating Segments \| Card services and ATM fees
Noninterest income
Noninterest income	0	0
FirsTech \| Operating Segments \| Other service charges on deposit accounts
Noninterest income
Noninterest income	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Schedule of Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis (Details) - Fair Value, Nonrecurring - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans evaluated individually, net of related allowance	$ 17,658	$ 19,604
Bank property held for sale with impairment	1,661	1,855
OREO and other repossessed assets with subsequent impairment
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
OREO and other repossessed assets with subsequent impairment	3,171	4,409
Level 1 Inputs
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans evaluated individually, net of related allowance	0	0
Bank property held for sale with impairment	0	0
Level 1 Inputs \| OREO and other repossessed assets with subsequent impairment
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
OREO and other repossessed assets with subsequent impairment	0	0
Level 2 Inputs
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans evaluated individually, net of related allowance	0	0
Bank property held for sale with impairment	0	0
Level 2 Inputs \| OREO and other repossessed assets with subsequent impairment
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
OREO and other repossessed assets with subsequent impairment	0	0
Level 3 Inputs
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans evaluated individually, net of related allowance	17,658	19,604
Bank property held for sale with impairment	1,661	1,855
Level 3 Inputs \| OREO and other repossessed assets with subsequent impairment
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
OREO and other repossessed assets with subsequent impairment	$ 3,171	$ 4,409

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)

3 Months Ended

Mar. 31, 2026

Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Alternative [Abstract]

Schedule of Accumulated Other Comprehensive Income (Loss)

The following tables present changes in AOCI by component, net of tax:


	Three Months Ended March 31, 2026
(dollars in thousands)	Unrealized Gains (Losses) on Debt Securities Available For Sale		Unrecognized Gains (Losses) on Debt Securities Held to Maturity		Unrealized Gains (Losses) on Cash Flow Hedges		Total
Balance, December 31, 2025	$	(98,693)	$	(18,164)	$	(7,616)	$	(124,473)
Unrealized holding gains (losses), net	(10,068)		—		(2,783)		(12,851)

Amounts reclassified from AOCI, net	(18)		—		1,052		1,034
Amortization of unrecognized losses on securities transferred to held to maturity	—		737		—		737
Balance, March 31, 2026	$	(108,779)	$	(17,427)	$	(9,347)	$	(135,553)


	Three Months Ended March 31, 2025
(dollars in thousands)	Unrealized Gains (Losses) on Debt Securities Available For Sale		Unrecognized Gains (Losses) on Debt Securities Held to Maturity		Unrealized Gains (Losses) on Cash Flow Hedges		Total
Balance, December 31, 2024	$	(165,680)	$	(21,554)	$	(19,805)	$	(207,039)
Unrealized holding gains (losses), net	16,581		—		4,641		21,222

Amounts reclassified from AOCI, net	11,374		—		1,505		12,879
Amortization of unrecognized losses on securities transferred to held to maturity	—		128		—		128
Balance, March 31, 2025	$	(137,725)	$	(21,426)	$	(13,659)	$	(172,810)

DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Net Gains (Losses) Relating to Derivative Instruments (Details) - Designated as Hedging Instrument - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Derivative [Line Items]
Net gains (losses) on mortgage banking derivatives	$ 140	$ 155
Interest rate lock commitments
Derivative [Line Items]
Net gains (losses) on mortgage banking derivatives	44	242
Forward sales commitments
Derivative [Line Items]
Net gains (losses) on mortgage banking derivatives	$ 96	$ (87)

OPERATING SEGMENTS AND RELATED INFORMATION - Schedule of Goodwill and Total Assets of Segments (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Segment Reporting Information [Line Items]
Goodwill	$ 382,363	$ 383,280
Total assets	18,036,622	18,104,736
Operating Segments \| Banking
Segment Reporting Information [Line Items]
Goodwill	359,263	360,180
Total assets	17,835,924	17,880,797
Operating Segments \| Wealth Management
Segment Reporting Information [Line Items]
Goodwill	14,108	14,108
Total assets	155,714	152,422
Operating Segments \| FirsTech
Segment Reporting Information [Line Items]
Goodwill	8,992	8,992
Total assets	44,964	45,373
Other
Segment Reporting Information [Line Items]
Goodwill	0	0
Total assets	$ 20	$ 26,144

- Definition

Amount of asset recognized for present right to economic benefit.

+ References

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- Definition

Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

+ References

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-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(10)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 14: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-4

+ Details

TAX CREDIT INVESTMENTS AND OTHER INVESTMENTS IN UNCONSOLIDATED ENTITIES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated entities	$ 175,596		$ 165,995
Deferred Income Taxes and Other Assets [Abstract]
Income tax credits and other tax benefits	4,925	$ 4,589
Amortization of investments in tax-advantaged projects	4,432	$ 4,108
Tax credit investments \| Other assets
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated entities	129,282		119,634
Other investments in unconsolidated entities \| Other assets
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated entities	46,314		46,361
Unfunded investment obligations \| Other liabilities
Schedule of Equity Method Investments [Line Items]
Unfunded investment obligations	$ 71,479		$ 68,690

SIGNIFICANT ACCOUNTING POLICIES

3 Months Ended

Mar. 31, 2026

Accounting Policies [Abstract]

SIGNIFICANT ACCOUNTING POLICIES

NOTE 1. SIGNIFICANT ACCOUNTING POLICIES

Nature of Operations

First Busey Corporation, a Nevada corporation organized in 1980, is an $18.04 billion financial holding company headquartered in Leawood, Kansas. Busey’s stock is traded on The Nasdaq Global Select Market, with its common stock trading under the symbol “BUSE” and its depositary shares of Busey Series B Preferred Stock trading under the symbol “BUSEP.”

Busey operates and reports its business in three segments: Banking, Wealth Management, and FirsTech.

•The Banking operating segment provides a full range of banking services to individual and corporate customers through its banking center network in Arizona, Colorado, Florida, Illinois, Indiana, Kansas, Missouri, New Mexico, Oklahoma, and Texas.

•The Wealth Management operating segment provides a full range of asset management, investment, brokerage, fiduciary, philanthropic advisory, tax preparation, and farm management services to individuals, businesses, and foundations.

•The FirsTech operating segment provides comprehensive and innovative payment technology solutions including online, mobile, and voice-recognition bill payments; money management and credit card networks; direct debit services; lockbox remittance processing for payments made by mail; and walk-in payments. FirsTech also provides additional tools to help clients with billing, reconciliation, bill reminders, and treasury services.

For additional information about Busey's operating segments, see “Note 16. Operating Segments and Related Information.”

Busey conducts its Banking and Wealth Management services through Busey Bank, and provides payment technology solutions through Busey Bank’s wholly owned subsidiary, FirsTech. Busey also has various other subsidiaries that are not significant to the consolidated entity.

Basis of Financial Statement Presentation

These unaudited consolidated financial statements and related notes should be read together with the audited consolidated financial statements included in Busey's 2025 Annual Report. These interim unaudited consolidated financial statements serve to update Busey’s 2025 Annual Report and may not include all information and notes necessary to constitute a complete set of financial statements.

Busey’s unaudited consolidated financial statements are prepared in conformity with GAAP, and reflect the elimination of intercompany accounts and transactions. Certain prior year amounts have been reclassified to conform to the current period presentation. These reclassifications did not have a material impact on Busey’s consolidated financial condition or results of operations.

In the opinion of Busey’s management, the unaudited consolidated financial statements reflect all normal, recurring adjustments needed to present fairly Busey’s results for the interim periods. The results of operations for interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period.

Use of Estimates

In preparing the accompanying unaudited consolidated financial statements in conformity with GAAP, Busey’s management is required to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and the disclosures provided. Actual results could differ from those estimates. Critical accounting estimates which are particularly susceptible to significant change relate to the fair value of assets acquired and liabilities assumed in business combinations, goodwill, income taxes, and the determination of the ACL.

Trust Assets

Assets held for customers in a fiduciary or agency capacity, other than trust cash on deposit at Busey Bank, are not Busey’s assets and, accordingly, are not included in the accompanying unaudited consolidated financial statements. Busey had assets under care of $15.65 billion at March 31, 2026, and $15.66 billion at December 31, 2025.

Cash and Cash Equivalents

Cash and cash equivalents include cash on hand, cash items in process of collection, amounts due from other banks, and interest-bearing deposits held with other financial institutions with original maturities of three months or less. The carrying amount of these instruments is considered a reasonable estimate of fair value.

Restrictions on Cash and Cash Equivalents

At March 31, 2026, cash and cash equivalents included $13.6 million contractually restricted by a third-party service provider, $14.4 million pledged to secure obligations under derivative contracts, and $68.1 million of reserved cash subject to call by the Federal Reserve Bank, as a member of the Federal Reserve System.

Interest-bearing time deposits in other banks

Interest-bearing time deposits in other banks consist of certificates of deposit with original maturities greater than three months and are carried at amortized cost.

Income Taxes

Busey is subject to income taxes in U.S. federal and various state jurisdictions. First Busey Corporation and its subsidiaries file consolidated federal and state income tax returns with each subsidiary computing its taxes on a separate entity basis. Tax regulations within each jurisdiction are subject to the interpretation of the related tax laws and regulations, which requires significant judgment. Busey monitors evolving federal and state tax legislation and its potential impact on operations on an ongoing basis.

As of March 31, 2026, Busey remains under examination by the Illinois Department of Revenue for M&M's tax filings for the tax years ended December 31, 2022 and 2023.

Preferred Stock

The following table summarizes Busey’s preferred stock issuances as of both March 31, 2026, and December 31, 2025:



Title of Each Issue	Shares Authorized	Shares Issued	Shares Outstanding	Par Value
Preferred stock, $0.001 par value:	1,000,000
Series A Non-Cumulative Perpetual Preferred Stock	7,750	7,750	7,750	$	7.75
8.25% Fixed-Rate Series B Non-Cumulative Perpetual Preferred Stock	230,000	215,000	215,000	$	215.00

Changes in preferred stock issued are presented in the following table:


	Three Months Ended March 31,
Title of Each Issue		2026		2025
Series A Non-Cumulative Perpetual Preferred Stock1		$	—	$	7.75
8.25% Fixed-Rate Series B Non-Cumulative Perpetual Preferred Stock2		—		N/A

___________________________________________

1.Busey Series A Preferred Stock was issued on March 1, 2025.

2.Busey Series B Preferred Stock was issued on May 20, 2025.

Impact of Recently Adopted Accounting Standards

In July 2025, the FASB issued ASU 2025-05 “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets,” providing a practical expedient which, if elected, permits an entity to assume that current conditions as of the balance sheet date will remain static for the remaining life of the assets, removing the requirement to consider reasonable, supportable forecasts. This ASU was adopted prospectively for annual and interim reporting periods beginning January 1, 2026. Adoption of this standard did not have a material impact on Busey’s financial position or results of operations.

In November 2024, the FASB issued ASU 2024-04 “Debt—Debt with Conversion and Other Options (Subtopic 470-20): Induced Conversions of Convertible Debt Instruments” to clarify when certain settlements of convertible debt instruments should be accounted for as an induced conversion. This ASU was adopted on a prospective basis for annual and interim reporting periods beginning January 1, 2026. Because Busey does not currently have any convertible debt, adoption of this standard did not have a material impact on Busey’s financial position or results of operations.

Recently Issued Accounting Standards Not Yet Adopted

In November 2025, the FASB issued ASU 2025-09 “Derivatives and Hedging (Topic 815): Hedge Accounting Improvements” to expand the hedged risks permitted to be aggregated in a group of individual forecasted transactions, enabling entities to apply hedge accounting treatment to a broader portfolio of forecasted transactions. Under the amendments in this update, a group of individual forecasted transactions can be designated as a cash flow hedge if they have a similar risk exposure. Individual forecasted transactions are considered to have a similar risk exposure when the derivative used as the hedging instrument is highly effective against each hedged risk in the group. This update is to be applied on a prospective basis for all hedging relationships; there is an option to elect to adopt the amendments in this update for hedging relationships that exist as of the date of adoption. This update will be effective for Busey for annual and interim reporting periods beginning January 1, 2027. Early adoption is permitted. Busey is currently evaluating the effect this ASU may have on its financial position and results of operations.

In September 2025, the FASB issued ASU 2025-07 “Derivatives and Hedging (Topic 815) and Revenue from Contracts with Customers (Topic 606): Derivatives Scope Refinements and Scope Clarification for Share-Based Noncash Consideration from a Customer in a Revenue Contract,” to reduce diversity in the application of derivative accounting practices. This update provides a scope limitation on the definition of a derivative subject to derivative accounting under ASC Topic 815, Derivatives and Hedging, to exclude certain non-exchange-traded contracts with contingencies based on operations or activities specific to one of the parties to the contract. In addition, this update clarifies that share-based noncash consideration from a customer that is contingent on the satisfaction of performance obligations should not be recognized at contract inception as a derivative asset or an equity security, but rather should be accounted for under the guidance in ASC Topic 606, Revenue from Contracts with Customers, and that guidance in other topics does not apply to share-based noncash consideration from a customer for the transfer of goods or services unless or until the entity’s right to receive or retain the share-based noncash consideration is unconditional under ASC Topic 606. The amendments in this update may be applied on either a prospective or modified retrospective basis, and will be effective for Busey for annual and interim reporting periods beginning January 1, 2027. Early adoption is permitted. Busey is currently evaluating the effect this ASU may have on its financial position and results of operations.

In September 2025, the FASB issued ASU 2025-06 “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software,” changing the criteria for capitalizing software costs to the following: (1) a commitment has been made to fund the software project, and (2) it is probable the project will be completed and used to perform its intended function. Under this update, software development stages are no longer a consideration in the determination of which costs are capitalized. The amendments in this update may be adopted on a prospective, modified transition, or retrospective basis, and will be effective for Busey for annual and interim reporting periods beginning January 1, 2028. Early adoption is permitted. Busey is currently evaluating the effect this ASU may have on its financial position and results of operations.

In November 2024, the FASB issued ASU 2024-03 “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses” to require additional disclosures within the notes to the financial statements about certain expense items. Specifically, disaggregation of income statement captions that contain expenses within the following five categories is required: (1) purchases of inventory, (2) employee compensation, (3) depreciation, (4) intangible asset amortization, and (5) depreciation, depletion, and amortization (“DD&A”) costs recognized as part of oil- and gas-producing activities or other amounts of depletion expense. Further, this update requires disclosure of the total amount of selling expenses and the entity’s definition of selling expenses. This update provides a practical expedient for banks and bank holding companies to continue presenting salaries and employee benefits in conformity with SEC Rule 210.9-04 instead of requiring those entities to apply the employee compensation definition included in Subtopic 220-40. The amendments in this update may be applied on either a prospective or retrospective basis and will be effective for Busey beginning with the annual reporting period ending December 31, 2027, and interim reporting periods beginning January 1, 2028. Early adoption is permitted. Because this update relates only to disclosure, Busey does not expect adoption of this ASU to have any impact on its financial position or results of operations.

In October 2023, the FASB issued ASU 2023‑06 “Disclosure Improvements: Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative” which aligns certain GAAP disclosure requirements with those of the SEC in order to better facilitate comparisons between SEC registrants and entities that are not subject to SEC reporting requirements. The amendments in this ASU should be applied prospectively, and the effective date will be the date on which the SEC removes the related disclosure from Regulation S‑X or Regulation S‑K. Early adoption is prohibited. If the SEC has not removed the related disclosures by June 30, 2027, the pending content of this update will be removed from the ASC and have no further effect. Because this update relates only to disclosure, Busey does not expect adoption of this ASU to have a material impact on its financial position or results of operations.

Subsequent Events

Busey has evaluated subsequent events for potential recognition and/or disclosure through the date the unaudited consolidated financial statements included in this Quarterly Report were issued. Effective April 30, 2026, Busey executed an amendment to its Second Amended and Restated Credit Agreement, pursuant to which: (1) Busey’s revolving line of credit increased to $50.0 million, (2) the interest rate on the revolving line of credit was reduced to the one-month Term SOFR rate plus 1.65%, and (3) the termination date for the agreement was extended to April 30, 2027. Other than this, there were no significant events subsequent to the quarter ended March 31, 2026, through the filing date of these unaudited consolidated financial statements.

DEBT SECURITIES

3 Months Ended

Mar. 31, 2026

Investments, Debt and Equity Securities [Abstract]

DEBT SECURITIES

NOTE 3. DEBT SECURITIES

Busey's portfolio of debt securities includes both available for sale and held to maturity securities. The tables below provide the amortized cost, unrealized or unrecognized gains and losses, and fair values of debt securities, summarized by major category:


	As of March 31, 2026
(dollars in thousands)	Amortized Cost		Unrealized				Fair Value
			Gross Gains		Gross Losses
Debt securities available for sale1

Obligations of U.S. government corporations and agencies	$	109,005	$	245	$	(244)	$	109,006
Obligations of states and political subdivisions	271,311		862		(12,119)		260,054
Asset-backed securities	246,728		100		(322)		246,506
Commercial mortgage-backed securities	160,476		272		(11,293)		149,455
Residential mortgage-backed securities	1,537,318		5,104		(132,751)		1,409,671
Corporate debt securities	42,183		243		(1,851)		40,575
Total debt securities available for sale	$	2,367,021	$	6,826	$	(158,580)	$	2,215,267



	Amortized Cost		Unrecognized				Fair Value
			Gross Gains		Gross Losses
Debt securities held to maturity
Commercial mortgage-backed securities	$	354,095	$	—	$	(66,759)	$	287,336
Residential mortgage-backed securities	371,445		—		(57,707)		313,738
Total debt securities held to maturity	$	725,540	$	—	$	(124,466)	$	601,074

___________________________________________

1.This table includes debt securities marked at par, with no gain or loss.


	As of December 31, 2025
(dollars in thousands)	Amortized Cost		Unrealized				Fair Value
			Gross Gains		Gross Losses
Debt securities available for sale1

Obligations of U.S. government corporations and agencies	$	111,876	$	250	$	(80)	$	112,046
Obligations of states and political subdivisions	270,682		3,089		(9,898)		263,873
Asset-backed securities	265,203		412		(35)		265,580
Commercial mortgage-backed securities	143,522		611		(11,191)		132,942
Residential mortgage-backed securities	1,464,347		9,336		(129,267)		1,344,416
Corporate debt securities	45,215		187		(1,711)		43,691
Total debt securities available for sale	$	2,300,845	$	13,885	$	(152,182)	$	2,162,548



	Amortized Cost		Unrecognized				Fair Value
			Gross Gains		Gross Losses
Debt securities held to maturity
Commercial mortgage-backed securities	$	367,825	$	—	$	(65,210)	$	302,615
Residential mortgage-backed securities	378,560		—		(55,218)		323,342
Total debt securities held to maturity	$	746,385	$	—	$	(120,428)	$	625,957

___________________________________________

1.This table includes debt securities marked at par, with no gain or loss.

Maturities of Debt Securities

Amortized cost and fair value of debt securities, by contractual maturity or pre-refunded date, are shown below. Mortgages underlying mortgage-backed securities and asset-backed securities may be called or prepaid; therefore, actual maturities could differ from the contractual maturities. All mortgage-backed securities were issued by U.S. government corporations and agencies.


	As of March 31, 2026
(dollars in thousands)	Amortized Cost		Fair Value
Debt securities available for sale
Due in one year or less	$	8,084	$	8,061
Due after one year through five years	85,282		82,185
Due after five years through ten years	351,875		335,172
Due after ten years	1,921,780		1,789,849
Debt securities available for sale	$	2,367,021	$	2,215,267

Debt securities held to maturity
Due in one year or less	$	9,946	$	9,906
Due after one year through five years	35,678		34,363

Due after ten years	679,916		556,805
Debt securities held to maturity	$	725,540	$	601,074

Gains and Losses on Debt Securities Available for Sale

Realized gains and losses related to sales and calls of debt securities available for sale are summarized as follows:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Realized gains and losses on debt securities
Gross gains on debt securities		$	24	$	8
Gross losses on debt securities1		(1)		(15,545)
Realized net gains (losses) on debt securities		$	23	$	(15,537)

___________________________________________

Debt securities with carrying amounts of $723.0 million on March 31, 2026, and $744.2 million on December 31, 2025, were pledged as collateral for public deposits, securities sold under agreements to repurchase, and for other purposes as required.

Debt Securities in an Unrealized or Unrecognized Loss Position


	As of March 31, 2026
	Less than 12 months				12 months or more				Total
(dollars in thousands)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Debt securities available for sale

Obligations of U.S. government corporations and agencies1	$	58,527	$	(244)	$	31	$	—	$	58,558	$	(244)
Obligations of states and political subdivisions	97,227		(2,076)		97,076		(10,043)		194,303		(12,119)
Asset-backed securities	83,728		(322)		—		—		83,728		(322)
Commercial mortgage-backed securities	6,505		(75)		71,215		(11,218)		77,720		(11,293)
Residential mortgage-backed securities	244,822		(2,558)		741,431		(130,193)		986,253		(132,751)
Corporate debt securities	2,440		(49)		26,444		(1,802)		28,884		(1,851)
Debt securities available for sale with gross unrealized losses	$	493,249	$	(5,324)	$	936,197	$	(153,256)	$	1,429,446	$	(158,580)




	Fair Value		Unrecognized Losses		Fair Value		Unrecognized Losses
Debt securities held to maturity
Commercial mortgage-backed securities	$	287,336	$	(66,759)	$	287,336	$	(66,759)
Residential mortgage-backed securities	313,738		(57,707)		313,738		(57,707)
Debt securities held to maturity with gross unrecognized losses	$	601,074	$	(124,466)	$	601,074	$	(124,466)

___________________________________________

1.Losses on securities in a continuous loss position for 12 months or more were immaterial, rounding to zero thousand.


	As of December 31, 2025
	Less than 12 months				12 months or more				Total
(dollars in thousands)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Debt securities available for sale

Obligations of U.S. government corporations and agencies	$	39,156	$	(80)	$	—	$	—	$	39,156	$	(80)
Obligations of states and political subdivisions	28,592		(361)		92,205		(9,537)		120,797		(9,898)
Asset-backed securities	10,005		(35)		—		—		10,005		(35)
Commercial mortgage-backed securities	4,986		(48)		71,830		(11,143)		76,816		(11,191)
Residential mortgage-backed securities	84,023		(708)		765,361		(128,559)		849,384		(129,267)
Corporate debt securities	5,969		(20)		29,097		(1,691)		35,066		(1,711)
Debt securities available for sale with gross unrealized losses	$	172,731	$	(1,252)	$	958,493	$	(150,930)	$	1,131,224	$	(152,182)




	Fair Value		Unrecognized Losses		Fair Value		Unrecognized Losses
Debt securities held to maturity
Commercial mortgage-backed securities	$	302,615	$	(65,210)	$	302,615	$	(65,210)
Residential mortgage-backed securities	323,342		(55,218)		323,342		(55,218)
Debt securities held to maturity with gross unrecognized losses	$	625,957	$	(120,428)	$	625,957	$	(120,428)

Additional information about debt securities in an unrealized or unrecognized loss position is presented in the tables below:


	As of March 31, 2026
(dollars in thousands)	Available for Sale			Held to Maturity			Total
Debt securities with gross unrealized or unrecognized losses, fair value	$	1,429,446		$	601,074		$	2,030,520
Gross unrealized or unrecognized losses on debt securities	158,580			124,466			283,046
Ratio of gross unrealized or unrecognized losses to debt securities with gross unrealized or unrecognized losses	11.1		%	20.7		%	13.9		%

Count of debt securities	637			52			689
Count of debt securities in an unrealized or unrecognized loss position	455			52			507


	As of December 31, 2025
(dollars in thousands)	Available for Sale			Held to Maturity			Total
Debt securities with gross unrealized or unrecognized losses, fair value	$	1,131,224		$	625,957		$	1,757,181
Gross unrealized or unrecognized losses on debt securities	152,182			120,428			272,610
Ratio of gross unrealized or unrecognized losses to debt securities with gross unrealized or unrecognized losses	13.5		%	19.2		%	15.5		%

Count of debt securities	637			52			689
Count of debt securities in an unrealized or unrecognized loss position	376			52			428

Unrealized and unrecognized losses were related to changes in market interest rates and market conditions that do not represent credit-related impairments. Unless part of a corporate strategy or restructuring plan, Busey does not intend to sell securities that are in an unrealized or unrecognized loss position, and it is more likely than not that Busey will recover the amortized cost prior to being required to sell the debt securities. Full collection of the amounts due according to the contractual terms of the debt securities is expected; therefore, no ACL has been recorded in relation to debt securities, and the impairment related to noncredit factors on debt securities available for sale is recognized in AOCI, net of applicable taxes. As of March 31, 2026, Busey did not hold general obligation bonds of any single issuer that exceeded, in aggregate, 10% of Busey’s stockholders’ equity.

BUSINESS COMBINATIONS - Narrative (Details) $ / shares in Thousands, $ in Thousands		3 Months Ended
	Mar. 01, 2025 USD ($) $ / shares shares	Mar. 31, 2026 USD ($) state	Dec. 31, 2025 USD ($)
Business Combination, Contingent Consideration [Line Items]
Number of states in which entity operates \| state		10
Preferred stock redemption price per share (in dollars per share) \| $ / shares	$ 1
Fair value adjustments		$ 900
Goodwill		$ 382,363	$ 383,280
CrossFirst
Business Combination, Contingent Consideration [Line Items]
Goodwill	$ 48,593
Fair value of financial assets acquired	4,700,000
Gross contractual amounts of acquired receivables	4,790,000
CrossFirst \| Replacement awards
Business Combination, Contingent Consideration [Line Items]
Common stock, preferred stock and replacement awards	$ 5,999
SSARs \| CrossFirst \| Common Stock \| CrossFirst
Business Combination, Contingent Consideration [Line Items]
Shares received for each share owned (in shares) \| shares	0.6675

PORTFOLIO LOANS (Tables)

3 Months Ended

Mar. 31, 2026

Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]

Schedule of Distribution of Portfolio Loans

Distributions of the loan portfolio by loan category and lending activity is presented in the following table:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Commercial loans
C&I and other commercial	$	4,124,737	$	4,229,208
CRE	5,566,044		5,550,018
Real estate construction	1,052,505		1,039,289
Total commercial loans	10,743,286		10,818,515
Retail loans
Retail real estate	2,119,621		2,154,616
Retail other	596,983		594,668
Total retail loans	2,716,604		2,749,284

Total portfolio loans	13,459,890		13,567,799
ACL	(169,054)		(174,023)
Portfolio loans, net	$	13,290,836	$	13,393,776

Schedule of Financial Instruments Owned and Pledged as Collateral


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Pledged loans
FHLB	$	7,199,169	$	5,051,512
Federal Reserve Bank	1,923,484		1,854,423
Total pledged loans	$	9,122,653	$	6,905,935

To secure its obligations under derivative contracts, Busey pledged cash and held collateral as follows:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Cash pledged to secure obligations under derivative contracts	$	14,400	$	14,400
Collateral held to secure obligations under derivative contracts	6,750		5,050

Schedule of Risk Grades of Portfolio Loans, Further Sorted by Origination

Risk grades of portfolio loans and gross charge-offs are presented in the tables below by lending activity, further sorted by origination year:


	As of and For The Three Months Ended March 31, 2026
Risk Grade Ratings	Term Loans Amortized Cost Basis by Origination Year												Revolving Loans		Total
(dollars in thousands)	2026		2025		2024		2023		2022		Prior
C&I and other commercial
Pass	$	176,684	$	703,182	$	444,948	$	281,266	$	190,104	$	247,451	$	1,356,182	$	3,399,817
Watch	5,980		37,677		79,414		54,522		30,451		48,220		164,690		420,954
Special Mention	6,657		18,453		12,256		19,335		21,324		6,427		61,112		145,564
Substandard	14,231		4,942		4,800		45,663		20,228		9,753		27,108		126,725
Substandard non-accrual	3		4,384		3,318		1,183		4,362		5,442		12,985		31,677
Total C&I and other commercial	203,555		768,638		544,736		401,969		266,469		317,293		1,622,077		4,124,737
Gross charge-offs	$	50	$	104	$	—	$	257	$	6,180	$	743	$	171	$	7,505

CRE
Pass	374,592		970,541		445,815		660,590		934,154		1,183,257		45,082		4,614,031
Watch	100,410		131,248		55,151		126,753		139,092		193,822		2,794		749,270
Special Mention	19,919		54,289		5,388		27,987		16,485		44,198		731		168,997
Substandard	1,234		2,122		421		3,243		3,860		12,184		215		23,279
Substandard non-accrual	—		519		253		5,366		483		3,846		—		10,467
Total CRE	496,155		1,158,719		507,028		823,939		1,094,074		1,437,307		48,822		5,566,044
Gross charge-offs	—		—		—		—		—		—		—		—

Real estate construction
Pass	102,064		373,586		251,234		69,954		69,315		7,516		74,606		948,275
Watch	13,896		2,153		—		1,978		42,561		160		6,198		66,946
Special Mention	—		18,945		—		—		—		6,434		—		25,379
Substandard	—		10,876		—		—		—		756		—		11,632
Substandard non-accrual	—		—		273		—		—		—		—		273
Total real estate construction	115,960		405,560		251,507		71,932		111,876		14,866		80,804		1,052,505
Gross charge-offs	—		—		—		—		—		—		—		—

Retail real estate
Pass	45,952		138,678		120,634		252,430		436,101		836,870		246,306		2,076,971
Watch	86		2,590		530		24,972		1,464		512		545		30,699
Special Mention	—		47		72		—		1,432		1,661		207		3,419
Substandard	—		—		—		4,108		135		1,100		—		5,343
Substandard non-accrual	—		357		308		127		579		1,058		760		3,189
Total retail real estate	46,038		141,672		121,544		281,637		439,711		841,201		247,818		2,119,621
Gross charge-offs	70		—		—		—		—		—		81		151

Retail other
Pass	750		4,850		1,889		29,179		26,892		5,245		527,985		596,790



Substandard non-accrual	—		—		—		76		116		—		1		193
Total retail other	750		4,850		1,889		29,255		27,008		5,245		527,986		596,983
Gross charge-offs	172		—		—		10		—		—		2		184

Total portfolio loans	$	862,458	$	2,479,439	$	1,426,704	$	1,608,732	$	1,939,138	$	2,615,912	$	2,527,507	$	13,459,890
Total gross charge-offs	$	292	$	104	$	—	$	267	$	6,180	$	743	$	254	$	7,840


	As of and For The Year Ended December 31, 2025
Risk Grade Ratings	Term Loans Amortized Cost Basis by Origination Year												Revolving Loans		Total
(dollars in thousands)	2025		2024		2023		2022		2021		Prior
C&I and other commercial
Pass	$	833,539	$	486,278	$	342,560	$	207,053	$	178,429	$	122,904	$	1,396,826	$	3,567,589
Watch	21,750		79,853		56,387		38,786		48,624		16,778		112,935		375,113
Special Mention	21,712		11,609		56,578		26,343		5,339		800		54,433		176,814
Substandard	8,336		605		20,444		14,603		9,868		3,655		17,883		75,394
Substandard non-accrual	1,489		3,899		600		10,265		948		4,560		12,537		34,298
Total C&I and other commercial	886,826		582,244		476,569		297,050		243,208		148,697		1,594,614		4,229,208
Gross charge-offs	$	4,667	$	3,332	$	4,347	$	1,450	$	13,591	$	11,456	$	5,716	$	44,559

CRE
Pass	1,077,169		483,950		710,448		1,035,426		740,680		515,631		43,830		4,607,134
Watch	210,673		61,926		119,986		143,072		161,387		69,789		2,572		769,405
Special Mention	49,648		22,642		2,991		13,811		32,109		18,858		908		140,967
Substandard	2,416		679		3,857		4,873		7,316		5,324		215		24,680
Substandard non-accrual	72		—		4,547		—		—		3,213		—		7,832
Total CRE	1,339,978		569,197		841,829		1,197,182		941,492		612,815		47,525		5,550,018
Gross charge-offs	1,297		11,057		—		—		253		—		—		12,607

Real estate construction
Pass	395,019		268,117		107,930		89,673		5,356		2,733		74,237		943,065
Watch	18,571		2,112		3,999		22,561		167		—		7,221		54,631
Special Mention	17,961		—		—		—		6,573		—		—		24,534
Substandard	16,020		—		—		—		766		—		—		16,786
Substandard non-accrual	—		273		—		—		—		—		—		273
Total real estate construction	447,571		270,502		111,929		112,234		12,862		2,733		81,458		1,039,289
Gross charge-offs	—		—		—		—		—		—		—		—

Retail real estate
Pass	93,212		127,475		269,877		446,309		407,851		508,504		252,987		2,106,215
Watch	2,686		569		24,601		1,492		267		482		577		30,674
Special Mention	47		78		4,028		1,454		1,686		—		214		7,507
Substandard	—		—		108		440		484		631		136		1,799
Substandard non-accrual	154		308		128		523		264		2,841		4,203		8,421
Total retail real estate	96,099		128,430		298,742		450,218		410,552		512,458		258,117		2,154,616
Gross charge-offs	1,164		—		—		—		—		51		36		1,251

Retail other
Pass	5,233		2,265		33,349		30,321		4,561		885		517,680		594,294



Substandard non-accrual	—		—		76		134		—		—		164		374
Total retail other	5,233		2,265		33,425		30,455		4,561		885		517,844		594,668
Gross charge-offs	546		147		270		47		—		74		141		1,225

Total portfolio loans	$	2,775,707	$	1,552,638	$	1,762,494	$	2,087,139	$	1,612,675	$	1,277,588	$	2,499,558	$	13,567,799
Total gross charge-offs	$	7,674	$	14,536	$	4,617	$	1,497	$	13,844	$	11,581	$	5,893	$	59,642

Schedule of Past Due and Non-accrual Loans and Non-Accrual Status

An analysis of portfolio loans that were past due and still accruing, or on a non-accrual status, is presented in the table below:


	As of March 31, 2026
	Loans Past Due, Still Accruing						Non-Accrual Loans		Non-Accrual Loans with No Allowance for Credit Losses
(dollars in thousands)	30-59 Days		60-89 Days		90+Days
Commercial loans
C&I and other commercial	$	2,828	$	412	$	518	$	31,677	$	7,451
CRE	2,195		—		—		10,467		3,726
Real estate construction	348		—		—		273		158
Past due and non-accrual commercial loans	5,371		412		518		42,417		11,335
Retail loans
Retail real estate	3,093		4,269		—		3,189		349
Retail other	4,290		30		294		193		—
Past due and non-accrual retail loans	7,383		4,299		294		3,382		349
Total past due and non-accrual loans	$	12,754	$	4,711	$	812	$	45,799	$	11,684


	As of December 31, 2025
	Loans Past Due, Still Accruing						Non-Accrual Loans		Non-Accrual Loans with No Allowance for Credit Losses
(dollars in thousands)	30-59 Days		60-89 Days		90+Days
Commercial loans
C&I and other commercial	$	3,577	$	593	$	2,128	$	34,298	$	4,612
CRE	484		2,514		—		7,832		1,588
Real estate construction	—		—		—		273		158
Past due and non-accrual commercial loans	4,061		3,107		2,128		42,403		6,358
Retail loans
Retail real estate	2,457		4,280		136		8,421		349
Retail other	2,491		79		24		374		—
Past due and non-accrual retail loans	4,948		4,359		160		8,795		349
Total past due and non-accrual loans	$	9,009	$	7,466	$	2,288	$	51,198	$	6,707

Schedule of Loan Modifications for Borrowers Experiencing Financial Difficulty


	Three Months Ended March 31, 2026
(dollars in thousands)	Payment Deferral		Term Extension		% of Total Class of Financing Receivable
Modified Loans
C&I and other commercial	$	2,215	$	34,349	0.9	%




Total loans modified during the period1	$	2,215	$	34,349	0.3	%

___________________________________________

1.Modifications were primarily for loans classified as substandard.


	Three Months Ended March 31, 2025
(dollars in thousands)	Payment Deferral		Term Extension		% of Total Class of Financing Receivable
Modified Loans
C&I and other commercial	$	10,832	$	21,923	0.7	%
CRE	—		4,719		0.1	%
Real estate construction	—		5,208		0.5	%


Total loans modified during the period1	$	10,832	$	31,850	0.3	%

___________________________________________

1.All modifications were for loans classified as substandard.

Three Months Ended March 31,

2026

2025

Weighted Average Term Extension

C&I and other commercial

10 months

1.9 years

CRE

—

6 months

Real estate construction

—

1.3 years

Aggregate effect

10 months

1.6 years

The following table depicts the payment performance of loans modified during the last twelve months:


	As of March 31, 2026
(dollars in thousands)	Current		30-89 Days		90+ Days		Non-accrual
Modified Loans
C&I and other commercial	$	42,179	$	—	$	—	$	4,476
CRE	1,833		—		—		273
Real estate construction	10,876		—		—		—


Loans modified during the last twelve months	$	54,888	$	—	$	—	$	4,749

Schedule of Modified Loans with Subsequent Defaults


	Three Months Ended March 31, 2026

(dollars in thousands)		Term Extension
Loans with Subsequent Defaults

CRE		$	273



Modified loans with subsequent defaults		$	273

Schedule of Loans Evaluated Individually, Segregated by Loan Category and Class


	Three Months Ended March 31, 2026
(dollars in thousands)	C&I and Other Commercial		CRE		Real Estate Construction		Retail Real Estate		Retail Other		Total
ACL balance, December 31, 2025	$	61,370	$	70,328	$	11,568	$	29,178	$	1,579	$	174,023


Provision for loan losses	3,556		(234)		1,019		(1,944)		(4)		2,393
Charged-off	(7,505)		—		—		(151)		(184)		(7,840)
Recoveries	383		6		1		57		31		478
ACL balance, March 31, 2026	$	57,804	$	70,100	$	12,588	$	27,140	$	1,422	$	169,054


	Three Months Ended March 31, 2025
(dollars in thousands)	C&I and Other Commercial		CRE		Real Estate Construction		Retail Real Estate		Retail Other		Total
ACL balance, December 31, 2024	$	21,589	$	32,301	$	3,345	$	23,711	$	2,458	$	83,404
Day 1 PCD1	75,569		21,588		2,112		1,430		84		100,783
Day 2 Provision for loan losses2	22,648		15,104		2,911		1,628		142		42,433
Provision for loan losses	623		(393)		311		(503)		(19)		19
Charged-off3	(31,221)		(253)		—		—		(361)		(31,835)
Recoveries	96		131		10		133		36		406
ACL balance, March 31, 2025	$	89,304	$	68,478	$	8,689	$	26,399	$	2,340	$	195,210

___________________________________________

1.The Day 1 PCD was attributable to the CrossFirst acquisition (see “Note 2. Business Combinations”), and represents the initial adjustment to the fair value of the PCD loans.

2.The Day 2 provision for loan losses was attributable to the CrossFirst acquisition (see “Note 2. Business Combinations”), and represents the initial provision for non-PCD loans.

3.Charged-off amounts included $29.6 million for PCD loans assumed in the CrossFirst acquisition, which were fully reserved at acquisition and did not require recording additional provision expense.

SIGNIFICANT ACCOUNTING POLICIES (Tables)

3 Months Ended

Mar. 31, 2026

Accounting Policies [Abstract]

Schedule of Stock Issuances

The following table summarizes Busey’s preferred stock issuances as of both March 31, 2026, and December 31, 2025:



Title of Each Issue	Shares Authorized	Shares Issued	Shares Outstanding	Par Value
Preferred stock, $0.001 par value:	1,000,000
Series A Non-Cumulative Perpetual Preferred Stock	7,750	7,750	7,750	$	7.75
8.25% Fixed-Rate Series B Non-Cumulative Perpetual Preferred Stock	230,000	215,000	215,000	$	215.00

Changes in preferred stock issued are presented in the following table:


	Three Months Ended March 31,
Title of Each Issue		2026		2025
Series A Non-Cumulative Perpetual Preferred Stock1		$	—	$	7.75
8.25% Fixed-Rate Series B Non-Cumulative Perpetual Preferred Stock2		—		N/A

___________________________________________

1.Busey Series A Preferred Stock was issued on March 1, 2025.

2.Busey Series B Preferred Stock was issued on May 20, 2025.

- Definition

Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information. Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.

+ References

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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(27))
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
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-Name Accounting Standards Codification
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-Paragraph 1
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-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-4

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
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-URI https://asc.fasb.org/1943274/2147481142/505-10-45-2

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-10

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

DEBT SECURITIES - Schedule of Realized Gains and Losses on Debt Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Realized gains and losses on debt securities
Gross gains on debt securities	$ 24	$ 8
Gross losses on debt securities	(1)	(15,545)
Realized net gains (losses) on debt securities	$ 23	(15,537)
Debt securities available for sale, sold		205,600
Pre-tax loss on debt securities		15,500
Debt securities available for sale sold, tax benefit		$ 4,300

PORTFOLIO LOANS - Schedule of the Financial Effect of Loan Modifications (Details)	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Loans identified as impaired
Weighted Average Term Extension	10 months	1 year 7 months 6 days
Commercial loans \| C&I and other commercial
Loans identified as impaired
Weighted Average Term Extension	10 months	1 year 10 months 24 days
Commercial loans \| CRE & Retail real estate
Loans identified as impaired
Weighted Average Term Extension		6 months
Commercial loans \| Real estate construction
Loans identified as impaired
Weighted Average Term Extension		1 year 3 months 18 days

OUTSTANDING COMMITMENTS AND CONTINGENT LIABILITIES

3 Months Ended

Mar. 31, 2026

Commitments and Contingencies Disclosure [Abstract]

OUTSTANDING COMMITMENTS AND CONTINGENT LIABILITIES

NOTE 11. OUTSTANDING COMMITMENTS AND CONTINGENT LIABILITIES

Commitments and Credit Risk

A summary of the contractual amount of Busey’s exposure to off-balance sheet risk relating to the Company’s commitments follows:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Off-Balance Sheet Commitments
Commitments to extend credit	$	4,601,629	$	4,696,867
Standby letters of credit	107,974		123,746
Total commitments	$	4,709,603	$	4,820,613

Legal Matters

Busey is a party to legal actions which arise in the normal course of its business activities. Additionally, on November 25, 2025, First Busey Corporation filed two lawsuits against the Illinois Secretary of State in connection with an ongoing dispute regarding the amount of franchise taxes, penalties, interest, fees, and charges purportedly due from First Busey Corporation to the Illinois Secretary of State, as described in more detail under the heading “Franchise Tax Matter” below. Legal and administrative proceedings are subject to inherent uncertainties. While unfavorable outcomes could occur, Busey does not believe at this time that any potential liabilities relating to pending or potential legal matters are likely to have a material impact on Busey's results of operations or financial position.

Franchise Tax Matter

In 2021, First Busey Corporation received an inquiry from the Illinois Secretary of State, pursuant to which the Illinois Secretary of State asked for additional information regarding certain of First Busey Corporation’s franchise tax filings and the calculation of amounts due thereunder. The franchise tax is established by the Illinois Business Corporation Act (“BCA”) 805 ILCS 5/1 et seq., and is a tax imposed on foreign and domestic corporations for the privilege of conducting business in Illinois. First Busey Corporation has been cooperating with the inquiry since the initial outreach from the Illinois Secretary of State in 2021 and in October 2024 delivered additional BCA forms requested by the Illinois Secretary of State, with a full reservation of rights by First Busey Corporation.

On March 20, 2025, the Illinois Secretary of State requested that First Busey Corporation resubmit the requested forms using a proposed methodology for paid-in capital that First Busey Corporation views as inconsistent with the Illinois Secretary of State’s past practice, and existing statutory and case law. Accordingly, on May 14, 2025, within the Illinois Secretary of State’s requested timeframe, First Busey Corporation informed the Illinois Secretary of State that it would not resubmit the requested forms with the methodology that First Busey Corporation disputes and requested that the parties instead continue good faith discussions. On July 2, 2025, First Busey Corporation received a notice of hearing from the Illinois Secretary of State indicating that an administrative hearing has been scheduled to “ascertain” the required amount of franchise taxes, penalties, interest, fees, and charges purportedly due from First Busey Corporation to the Illinois Secretary of State. In the notice, the Illinois Secretary of State requested a determination of an amount due that the Illinois Secretary of State preliminarily estimated in excess of $28.0 million, including in excess of $17.4 million in interest and approximately $0.3 million in penalties. First Busey Corporation disagrees with the Illinois Secretary of State’s preliminary estimate and believes that the Illinois Secretary of State’s request is contrary not only to the Illinois Secretary of State’s past practice, but also existing statutory and case law. First Busey Corporation intends to vigorously defend itself against the Illinois Secretary of State’s notice, including through appropriate judicial relief. To that end, on July 31, 2025, First Busey Corporation filed a special appearance with the Illinois Secretary of State’s Department of Administrative Hearings solely for the limited purpose of contesting the jurisdiction of the Illinois Secretary of State to initiate and conduct the administrative hearing, and on November 25, 2025, First Busey Corporation filed two lawsuits against the Illinois Secretary of State in connection with this matter: one in federal court, First Busey Corporation v. Alexi Giannoulias, No. 3:25-cv-50488 (N.D. Ill.); and one in Illinois state court, First Busey Corporation v. Alexi Giannoulias, No. 25-MR-283 (Sixth Judicial Circuit of Illinois, Champaign County). Both lawsuits and the administrative hearing remain pending.

Where a loss is believed to be reasonably possible, but not probable, or the loss cannot be reasonably estimated, no accrual is required. Given the underlying disagreement between First Busey Corporation and the Illinois Secretary of State on the proper methodology for calculating any franchise tax owed, the loss cannot be reasonably estimated. It is reasonably possible that this matter could require First Busey Corporation to pay additional taxes, including potential penalties and interest, or make other expenditures or accrue liabilities in amounts that could not be reasonably estimated as of March 31, 2026. If the likelihood of potential liabilities elevates and First Busey Corporation becomes able to reasonably estimate the loss, requiring an accrual, the potential future liabilities could be material in the period(s) in which they are recorded.

DEBT SECURITIES - Schedule of Amortized Cost, Unrealized or Unrecognized Gains and Losses, and Fair Values of Securities Classified as AFS and HTM (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Debt securities available for sale
Amortized Cost	$ 2,367,021	$ 2,300,845
Unrealized gross gains	6,826	13,885
Unrealized gross losses	(158,580)	(152,182)
Fair Value	2,215,267	2,162,548
Debt securities held to maturity
Amortized Cost	725,540	746,385
Unrecognized gross gains	0	0
Unrecognized gross losses	(124,466)	(120,428)
Fair Value	601,074	625,957
Obligations of U.S. government corporations and agencies
Debt securities available for sale
Amortized Cost	109,005	111,876
Unrealized gross gains	245	250
Unrealized gross losses	(244)	(80)
Fair Value	109,006	112,046
Obligations of states and political subdivisions
Debt securities available for sale
Amortized Cost	271,311	270,682
Unrealized gross gains	862	3,089
Unrealized gross losses	(12,119)	(9,898)
Fair Value	260,054	263,873
Asset-backed securities
Debt securities available for sale
Amortized Cost	246,728	265,203
Unrealized gross gains	100	412
Unrealized gross losses	(322)	(35)
Fair Value	246,506	265,580
Commercial mortgage-backed securities
Debt securities available for sale
Amortized Cost	160,476	143,522
Unrealized gross gains	272	611
Unrealized gross losses	(11,293)	(11,191)
Fair Value	149,455	132,942
Debt securities held to maturity
Amortized Cost	354,095	367,825
Unrecognized gross gains	0	0
Unrecognized gross losses	(66,759)	(65,210)
Fair Value	287,336	302,615
Residential mortgage-backed securities
Debt securities available for sale
Amortized Cost	1,537,318	1,464,347
Unrealized gross gains	5,104	9,336
Unrealized gross losses	(132,751)	(129,267)
Fair Value	1,409,671	1,344,416
Debt securities held to maturity
Amortized Cost	371,445	378,560
Unrecognized gross gains	0	0
Unrecognized gross losses	(57,707)	(55,218)
Fair Value	313,738	323,342
Corporate debt securities
Debt securities available for sale
Amortized Cost	42,183	45,215
Unrealized gross gains	243	187
Unrealized gross losses	(1,851)	(1,711)
Fair Value	$ 40,575	$ 43,691

BORROWINGS - Short-term Borrowings - Narrative (Details) - note	3 Months Ended
	Mar. 31, 2026	Dec. 31, 2025
Short-Term Debt [Line Items]
Debt, weighted average interest rate (as a percent)	2.40%	2.22%
FHLB advances maturing in less than one year from date of origination, and the current portion of long-term FHLB advances due within 12 months
Short-Term Debt [Line Items]
Number of notes	2
Debt, weighted average interest rate (as a percent)	3.80%
Debt, weighted average maturity period	1 day
Minimum
Short-Term Debt [Line Items]
Short-term borrowings, mature period	1 day
Maximum
Short-Term Debt [Line Items]
Short-term borrowings, mature period	90 days

BORROWINGS - Schedule of Securities Sold Under Agreements to Repurchase (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Debt Disclosure [Abstract]
Securities sold under agreements to repurchase	$ 156,364	$ 166,929
Weighted average rate for securities sold under agreements to repurchase	2.40%	2.22%

- Definition

Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
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-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

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+ Details

DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Reclassification of Unrealized Gains and Losses from OCI (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2026 USD ($)
Interest Rate Swap \| Cash Flow Hedging \| Interest Income
Derivative [Line Items]
Unrealized gains expected to be reclassified from OCI to interest income	$ 481

BORROWINGS (Tables)

3 Months Ended

Mar. 31, 2026

Debt Disclosure [Abstract]

Schedule of Securities Sold Under Agreements to Repurchase

Securities sold under agreements to repurchase were as follows:


	As of
(dollars in thousands)	March 31, 2026			December 31, 2025
Securities sold under agreements to repurchase	$	156,364		$	166,929
Weighted average rate for securities sold under agreements to repurchase	2.40		%	2.22		%

Schedule of Short-term Borrowings

Short-term borrowings are presented in the table below:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Short-term borrowings

FHLB advances maturing in less than one year from date of origination, and the current portion of long-term FHLB advances due within 12 months	$	170,000	$	—


Total short-term borrowings	$	170,000	$	—

Schedule of Long-term Borrowings

Long-term borrowings are presented in the table below:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Long-term borrowings
FHLB borrowings	$	114,078	$	102,792
Secured borrowings	3,211		4,791

Finance lease liabilities	6,178		6,223
Total long-term borrowings	$	123,467	$	113,806

Schedule of Unamortized Debt Issuance Cost

Unamortized debt issuance costs related to Busey’s subordinated notes are presented in the following table:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025



Unamortized debt issuance costs	$	501	$	605

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

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+ Details

CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Cash and cash equivalents:
Cash and due from banks	$ 169,041	$ 181,041
Interest-bearing deposits	119,421	99,186
Total cash and cash equivalents	288,462	280,227
Interest-bearing time deposits in other banks	13,725	13,825
Debt securities available for sale	2,215,267	2,162,548
Debt securities held to maturity	725,540	746,385
Equity securities	13,951	14,916
Loans held for sale	5,224	5,752
Portfolio loans (net of ACL of $169,054 at March 31, 2026, and $174,023 at December 31, 2025)	13,290,836	13,393,776
Restricted bank stock	81,722	77,006
Premises and equipment, net	193,322	193,444
Goodwill	382,363	383,280
Other intangible assets, net	93,157	97,449
Cash surrender value of bank owned life insurance	262,061	260,402
Other assets	470,992	475,726
Total assets	18,036,622	18,104,736
Deposits:
Noninterest-bearing	3,526,036	3,659,421
Interest-bearing	11,210,024	11,246,537
Total deposits	14,736,060	14,905,958
Securities sold under agreements to repurchase	156,364	166,929
Short-term borrowings	170,000	0
Long-term borrowings	123,466	113,806
Subordinated notes, net of unamortized issuance costs	99,499	99,395
Junior subordinated debt owed to unconsolidated trusts	77,400	77,328
Other liabilities	260,811	272,338
Total liabilities	15,623,600	15,635,754
Outstanding commitments and contingent liabilities (see Notes 5 and 11)
Stockholders’ equity
Preferred stock, $0.001 par value, liquidation preference $222,750 at March 31, 2026, and December 31, 2025	0	0
Common stock, $0.001 par value	93	93
Additional paid-in capital	2,361,959	2,375,511
Retained earnings	359,162	336,707
AOCI	(135,553)	(124,473)
Total stockholders’ equity before treasury stock	2,585,661	2,587,838
Treasury stock at cost	(172,639)	(118,856)
Total stockholders’ equity	2,413,022	2,468,982
Total liabilities and stockholders’ equity	$ 18,036,622	$ 18,104,736
Preferred shares issued (in shares)	222,750	222,750
Preferred shares outstanding (in shares)	222,750	222,750
Common shares issued (in shares)	92,694,541	92,694,541
Less: Treasury (in shares)	7,187,381	5,070,111
Common stock outstanding (in shares)	85,507,160	87,624,430

BUSINESS COMBINATIONS - Schedule of Estimated Acquisition-date Fair Values of the Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Mar. 01, 2025	Mar. 31, 2026	Dec. 31, 2025
Consideration paid
Goodwill		$ 382,363	$ 383,280
CrossFirst
Assets acquired
Cash and cash equivalents	$ 385,808
Securities	725,622
Portfolio loans, net of ACL	6,023,063
Premises and equipment	69,673
Other intangible assets	81,783
Other assets	213,352
Total assets acquired	7,499,301
Liabilities assumed
Deposits	6,571,699
Short-term borrowings	11,148
Long-term borrowings	68,922
Junior subordinated debt owed to unconsolidated trusts	2,238
Other liabilities	84,907
Total liabilities assumed	6,738,914
Net assets acquired	760,387
Consideration paid
Cash	4
Total consideration paid	808,980
Goodwill	$ 48,593
Useful life	10 years
CrossFirst \| Common
Consideration paid
Common stock, preferred stock and replacement awards	$ 795,227
CrossFirst \| Preferred stock
Consideration paid
Common stock, preferred stock and replacement awards	7,750
CrossFirst \| Replacement awards
Consideration paid
Common stock, preferred stock and replacement awards	$ 5,999

DEBT SECURITIES - Schedule of Maturity of Debt Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Amortized Cost
Due in one year or less	$ 8,084
Due after one year through five years	85,282
Due after five years through ten years	351,875
Due after ten years	1,921,780
Amortized Cost	2,367,021	$ 2,300,845
Fair Value
Due in one year or less	8,061
Due after one year through five years	82,185
Due after five years through ten years	335,172
Due after ten years	1,789,849
Fair Value	2,215,267	2,162,548
Amortized Cost
Due in one year or less	9,946
Due after one year through five years	35,678
Due after ten years	679,916
Amortized Cost	725,540	746,385
Fair Value
Due in one year or less	9,906
Due after one year through five years	34,363
Due after ten years	556,805
Fair Value	$ 601,074	$ 625,957

BORROWINGS - Subordinated Notes (Details) - 5.000% Notes Maturing June 15, 2032 - Subordinated Debt $ in Millions	Jun. 02, 2022 USD ($)
Debt Instrument [Line Items]
Principal balance	$ 100.0
Interest rate	5.00%
Percentage of principal amount of notes	100.00%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) [Member]
Floating interest rate margin (as a percent)	2.52%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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-Paragraph 1F
-Subparagraph (b)(1)
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Reference 28: http://www.xbrl.org/2003/role/disclosureRef
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Reference 29: http://www.xbrl.org/2003/role/disclosureRef
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Reference 30: http://www.xbrl.org/2009/role/commonPracticeRef
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-URI https://asc.fasb.org/1943274/2147482900/835-30-50-1

+ Details

PORTFOLIO LOANS - Schedule of Performance of Modified Loans (Details) $ in Thousands	Mar. 31, 2026 USD ($)
Loans identified as impaired
Non-accrual	$ 4,749
Current
Loans identified as impaired
Current	54,888
30-89 Days
Loans identified as impaired
Current	0
90+ Days
Loans identified as impaired
Current	0
Commercial loans \| C&I and other commercial
Loans identified as impaired
Non-accrual	4,476
Commercial loans \| C&I and other commercial \| Current
Loans identified as impaired
Current	42,179
Commercial loans \| C&I and other commercial \| 30-89 Days
Loans identified as impaired
Current	0
Commercial loans \| C&I and other commercial \| 90+ Days
Loans identified as impaired
Current	0
Commercial loans \| CRE and Retail real estate
Loans identified as impaired
Non-accrual	273
Commercial loans \| CRE and Retail real estate \| Current
Loans identified as impaired
Current	1,833
Commercial loans \| CRE and Retail real estate \| 30-89 Days
Loans identified as impaired
Current	0
Commercial loans \| CRE and Retail real estate \| 90+ Days
Loans identified as impaired
Current	0
Commercial loans \| Real estate construction
Loans identified as impaired
Non-accrual	0
Commercial loans \| Real estate construction \| Current
Loans identified as impaired
Current	10,876
Commercial loans \| Real estate construction \| 30-89 Days
Loans identified as impaired
Current	0
Commercial loans \| Real estate construction \| 90+ Days
Loans identified as impaired
Current	$ 0

BUSINESS COMBINATIONS

3 Months Ended

Mar. 31, 2026

Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract]

BUSINESS COMBINATIONS

NOTE 2. BUSINESS COMBINATIONS

CrossFirst Bankshares, Inc.

On March 1, 2025, Busey completed its acquisition of CrossFirst (NASDAQ: CFB), the holding company for CrossFirst Bank, pursuant to an Agreement and Plan of Merger, dated August 26, 2024, by and between Busey and CrossFirst (the “CrossFirst Merger Agreement”). This partnership created a premier commercial bank spanning 10 states—Illinois, Missouri, Texas, Colorado, Florida, Kansas, Oklahoma, Arizona, Indiana, and New Mexico. The combined holding company operates under the First Busey Corporation name. Busey’s common stock continues to trade on the Nasdaq under the “BUSE” stock ticker symbol.

Merger of CrossFirst Bank into Busey Bank

CrossFirst Bank’s results of operations were included in Busey’s consolidated results of operations beginning March 1, 2025. Busey operated CrossFirst Bank as a separate banking subsidiary until it was merged with and into Busey Bank on June 20, 2025. At the time of the bank merger, CrossFirst Bank’s banking centers became banking centers of Busey Bank.

Merger Consideration for CrossFirst

Upon completion of the acquisition, each share of CrossFirst common stock converted into the right to receive 0.6675 of a share of Busey’s common stock. Cash was paid in lieu of fractional shares. The fair value of common shares issued in consideration of the CrossFirst acquisition was based on the closing price of Busey’s common stock on February 28, 2025.

Further, upon completion of the acquisition, each share of CrossFirst Series A Non-Cumulative Perpetual Preferred Stock converted to the right to receive one share of Busey Series A Preferred Stock. The fair value of Busey Series A Preferred Stock was based on the redemption price of $1,000 per share.

The total consideration paid also included the fair value of replacement equity awards related to past service totaling $6.0 million. Busey used a Monte Carlo simulation to estimate the fair value of SSARs and market-based awards. Other awards were valued based on Busey’s closing stock price on February 28, 2025.

Acquisition Accounting for CrossFirst

The CrossFirst acquisition was accounted for using the acquisition method of accounting and, accordingly, assets acquired, liabilities assumed, and consideration exchanged were recorded at estimated fair values as of March 1, 2025, the date of acquisition. Fair values, including initial accounting for deferred taxes, were subject to refinement for up to one year after the closing date as additional information regarding the closing date fair values became available. A final fair value adjustment for deferred taxes was recorded during the three months ended March 31, 2026, resulting in a $0.9 million increase to the fair value of net assets acquired. Fair values are now final.

As the total consideration paid for CrossFirst exceeded the estimated fair value of net assets acquired, goodwill of $48.6 million was recorded as a result of the acquisition. Goodwill recorded for this transaction reflects synergies expected from the acquisition and the greater revenue opportunities from Busey’s broader service capabilities in attractive new markets. Goodwill recorded for this transaction is not tax deductible and was assigned to the Banking operating segment.

Acquisition Date Fair Values

Acquisition-date fair values of the assets acquired and liabilities assumed, as well as the fair value of consideration transferred, were estimated as follows:


	As of
	March 1, 2025
(dollars in thousands)	(final)
Assets acquired
Cash and cash equivalents	$	385,808
Securities	725,622
Portfolio loans, net of ACL	6,023,063
Premises and equipment	69,673

Other intangible assets1	81,783
Other assets	213,352
Total assets acquired	7,499,301

Liabilities assumed
Deposits	6,571,699
Short-term borrowings	11,148
Long-term borrowings	68,922

Junior subordinated debt owed to unconsolidated trusts	2,238

Other liabilities	84,907
Total liabilities assumed	6,738,914

Net assets acquired	$	760,387

Consideration paid
Cash	$	4
Common stock	795,227
Preferred stock	7,750
Replacement awards2	5,999
Total consideration paid	$	808,980

Goodwill	$	48,593

___________________________________________

1.Other intangible assets are being amortized over a period of ten years.

2.Represents the fair value of replacement equity awards issued to CrossFirst associates attributable to pre-combination service.

Valuations of Loans

Estimated fair values for the loan portfolio acquired in the CrossFirst acquisition includes adjustments to certain receivables that were not considered PCD as of the acquisition date. These fair value adjustments were determined using a discounted cash flow model that applies various assumptions about coupon rates, remaining maturities, prepayment speeds, projected default probabilities, losses given default, and estimates of prevailing discount rates. These loans did not show signs of deterioration since origination, and therefore, at the acquisition date, were not subject to the guidance related to PCD loans. Receivables acquired in the CrossFirst acquisition that were not subject to these requirements include non-PCD loans with a fair value of $4.70 billion and gross contractual amounts receivable of $4.79 billion.

A portion of acquired loans were PCD. The following table provides a reconciliation between the purchase price and the fair value of these financial assets:


	As of
(dollars in thousands)	March 1, 2025

PCD Financial Assets
Gross contractual receivable for PCD financial assets	$	1,539,718
ACL recorded for estimated uncollectible contractual cash flows specific to PCD financial assets	(100,783)
Interest premium (discount) specific to PCD financial assets	(3,063)
Loans previously charged-off prior to acquisition	(110,740)
Fair value of PCD financial assets	$	1,325,132

Pro Forma Results

The following unaudited pro forma information has been prepared as if the CrossFirst acquisition had occurred on January 1, 2024. The pro forma results combine CrossFirst’s historical results into Busey’s Consolidated Statements of Income (Unaudited), including the impact of estimated purchase accounting adjustments such as loan discount accretion, intangible assets amortization, and deposit accretion, net of taxes, which may not align with the timing of actual results. The pro forma results have been prepared for comparative purposes only and are not necessarily indicative of the results that would have been obtained had the acquisition actually occurred on January 1, 2024. Further, pro forma information does not purport to be indicative of future financial operating results. No assumptions have been applied to the pro forma results of operations regarding possible revenue enhancements, expense efficiencies, or asset dispositions. Only the acquisition-related expenses that have been recognized are included in net income in the table below:



(dollars in thousands)	Three Months Ended March 31, 2025
Revenue (net interest income plus noninterest income)	$	171,157
Net income	20,241

Other Acquisition Costs

Busey incurred acquisition-related expenses as follows:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Pre-tax acquisition expenses
CrossFirst1		$	5,244	$	71,490
M&M2		—		108
Pre-tax acquisition expenses		$	5,244	$	71,598

___________________________________________

Of the total acquisition-related expenses, the following legal, professional, and consulting costs were incurred to consummate the merger:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025



Pre-tax costs to consummate the merger		$	119	$	7,144

- Definition

The entire disclosure for business combination.

+ References

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+ Details

DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Derivative Assets and Liabilities Related to Foreign Currency Contracts (Details) - Foreign currency exchange forward contracts - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Customer contracts
Derivative [Line Items]
Notional Amount	$ 3,531	$ 0
Fair Value	211	0
Third-party dealer contracts
Derivative [Line Items]
Notional Amount	629	0
Fair Value	$ 6	$ 0

DEPOSITS - Schedule of Composition of Deposits (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Deposits [Abstract]
Noninterest-bearing demand deposits	$ 3,526,036	$ 3,659,421
Interest-bearing transaction deposits	3,129,186	3,119,475
Saving deposits and money market deposits	5,714,697	5,697,172
Time deposits	2,366,141	2,429,890
Total deposits	14,736,060	14,905,958
Brokered interest-bearing transaction deposits	50,119	50,136
Brokered savings deposits and money market deposits	10,004	10,000
Brokered time deposits	0	10,004
Aggregate amount of time deposits with a minimum denomination of $100,000	1,637,485	1,674,862
Aggregate amount of time deposits with a minimum denomination that meets or exceeds the FDIC insurance limit of $250,000	$ 865,493	$ 876,207

LEASES - Schedule of Revenue Recorded in Connection with Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Leases [Abstract]
Rental income	$ 214	$ 216

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)

3 Months Ended

Mar. 31, 2026

Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Alternative [Abstract]

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)

NOTE 15. ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)

The following tables present changes in AOCI by component, net of tax:


	Three Months Ended March 31, 2026
(dollars in thousands)	Unrealized Gains (Losses) on Debt Securities Available For Sale		Unrecognized Gains (Losses) on Debt Securities Held to Maturity		Unrealized Gains (Losses) on Cash Flow Hedges		Total
Balance, December 31, 2025	$	(98,693)	$	(18,164)	$	(7,616)	$	(124,473)
Unrealized holding gains (losses), net	(10,068)		—		(2,783)		(12,851)

Amounts reclassified from AOCI, net	(18)		—		1,052		1,034
Amortization of unrecognized losses on securities transferred to held to maturity	—		737		—		737
Balance, March 31, 2026	$	(108,779)	$	(17,427)	$	(9,347)	$	(135,553)


	Three Months Ended March 31, 2025
(dollars in thousands)	Unrealized Gains (Losses) on Debt Securities Available For Sale		Unrecognized Gains (Losses) on Debt Securities Held to Maturity		Unrealized Gains (Losses) on Cash Flow Hedges		Total
Balance, December 31, 2024	$	(165,680)	$	(21,554)	$	(19,805)	$	(207,039)
Unrealized holding gains (losses), net	16,581		—		4,641		21,222

Amounts reclassified from AOCI, net	11,374		—		1,505		12,879
Amortization of unrecognized losses on securities transferred to held to maturity	—		128		—		128
Balance, March 31, 2025	$	(137,725)	$	(21,426)	$	(13,659)	$	(172,810)

DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Interest Income (Expense) Recorded on Swap Transactions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Interest Rate Swap \| Cash Flow Hedging
Derivative [Line Items]
Decrease in interest income on swap transactions	$ (1,403)	$ (2,060)

FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Mar. 31, 2026

Fair Value Disclosures [Abstract]

Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis

The following tables summarize financial assets and financial liabilities measured at estimated fair value on a recurring basis:


	As of March 31, 2026
(dollars in thousands)	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Debt securities available for sale:

Obligations of U.S. government corporations and agencies	$	—	$	109,006	$	—	$	109,006
Obligations of states and political subdivisions	—		260,054		—		260,054
Asset-backed securities	—		246,506		—		246,506
Commercial mortgage-backed securities	—		149,455		—		149,455
Residential mortgage-backed securities	—		1,409,671		—		1,409,671
Corporate debt securities	—		40,575		—		40,575
Equity securities	131		13,820		—		13,951
Derivative assets	—		26,589		22		26,611
Derivative liabilities	—		39,917		48		39,965


	As of December 31, 2025
(dollars in thousands)	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Debt securities available for sale:

Obligations of U.S. government corporations and agencies	$	—	$	112,046	$	—	$	112,046
Obligations of states and political subdivisions	—		263,873		—		263,873
Asset-backed securities	—		265,580		—		265,580
Commercial mortgage-backed securities	—		132,942		—		132,942
Residential mortgage-backed securities	—		1,344,416		—		1,344,416
Corporate debt securities	—		43,691		—		43,691
Equity securities	155		14,761		—		14,916
Derivative assets	—		30,902		30		30,932
Derivative liabilities	—		42,155		65		42,220

Activity for Busey's risk participation agreements, which are measured at estimated fair value on a recurring basis using Level 3 inputs, is summarized in the table below:


		Three Months Ended March 31,
(dollars in thousands)	Location		2026		2025
Beginning Balance			$	(35)	$	5
Gains (losses) recognized in earnings	Other noninterest expense		9		2
Gains (losses) recognized in earnings1	Other noninterest income		—		(11)


Sales			—		6
Assumed in business combinations2			—		(41)




Ending Balance			$	(26)	$	(39)

___________________________________________

2.Represents risk participation agreements assumed in the CrossFirst acquisition.

Schedule of Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis

The following tables summarize financial assets and financial liabilities measured at estimated fair value on a non-recurring basis:


	As of March 31, 2026
(dollars in thousands)	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Loans evaluated individually, net of related allowance	$	—	$	—	$	17,658	$	17,658
OREO and other repossessed assets with subsequent impairment	—		—		3,171		3,171
Bank property held for sale with impairment	—		—		1,661		1,661


	As of December 31, 2025
(dollars in thousands)	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Loans evaluated individually, net of related allowance	$	—	$	—	$	19,604	$	19,604
OREO and other repossessed assets with subsequent impairment	—		—		4,409		4,409
Bank property held for sale with impairment	—		—		1,855		1,855

Schedule of Quantitative Information About Level 3 Fair Value Measurements

The following tables present additional quantitative information about assets measured at estimated fair value on a non-recurring basis using Level 3 inputs:

As of March 31, 2026

(dollars in thousands)

Fair Value

Valuation
Techniques

Unobservable
Input

Range
(Weighted Average)

Loans evaluated individually, net of related allowance

17,658

Appraisal of collateral

Appraisal adjustments

-1.6% to -100.0%

(-41.4)%

OREO and other repossessed assets with subsequent impairment

3,171

Appraisal of collateral

Appraisal adjustments

-3.5% to -24.1%

(-3.9)%

Bank property held for sale with impairment

1,661

Appraisal of collateral or real estate listing price

Appraisal adjustments

-9.0% to -46.1%

(-36.1)%

As of December 31, 2025

(dollars in thousands)

Fair Value

Valuation
Techniques

Unobservable
Input

Range
(Weighted Average)

Loans evaluated individually, net of related allowance

19,604

Appraisal of collateral

Appraisal adjustments

-1.6% to -100.0%

(-44.6)%

OREO and other repossessed assets with subsequent impairment

4,409

Appraisal of collateral

Appraisal adjustments

-2.8% to -24.1%

(-4.5)%

Bank property held for sale with impairment

1,855

Appraisal of collateral or real estate listing price

Appraisal adjustments

-9.0% to -58.0%

(-39.4)%

Schedule of Estimated Fair Values of Financial Instruments

Fair values of financial instruments that are not carried at fair value on Busey’s Consolidated Balance Sheets (Unaudited) were estimated as follows:


	As of March 31, 2026				As of December 31, 2025
(dollars in thousands)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Financial assets
Level 1 inputs:
Cash and cash equivalents	$	288,462	$	288,462	$	280,227	$	280,227
Level 2 inputs:
Interest-bearing time deposits in other banks	13,725		11,791		13,825		11,880
Debt securities held to maturity	725,540		601,074		746,385		625,957
Loans held for sale	5,224		5,255		5,752		5,886
Restricted bank stock	81,722		81,722		77,006		77,006
Accrued interest receivable	73,110		73,110		71,788		71,788
Level 3 inputs:
Portfolio loans, net	13,290,836		13,356,367		13,393,776		13,472,907
Mortgage servicing rights	1,577		5,239		1,459		5,176
Other servicing rights	2,086		2,265		2,086		2,193

Financial liabilities
Level 2 inputs:
Time deposits	$	2,366,141	$	2,358,640	$	2,429,890	$	2,425,290
Securities sold under agreements to repurchase	156,364		156,364		166,929		166,929
Short-term borrowings	170,000		170,000		—		—
Long-term borrowings	123,466		122,835		113,806		113,853
Junior subordinated debt owed to unconsolidated trusts	77,400		73,037		77,328		71,407
Accrued interest payable	26,186		26,186		25,372		25,372
Level 3 inputs:

Subordinated notes, net of unamortized issuance costs	99,499		96,750		99,395		94,500

OUTSTANDING COMMITMENTS AND CONTINGENT LIABILITIES - Narrative (Details) $ in Millions	Jul. 02, 2025 USD ($)	Nov. 25, 2025 lawsuit
Other Commitments [Line Items]
Income tax examination, number of lawsuits filed \| lawsuit		2
Federal
Other Commitments [Line Items]
Income tax examination, number of lawsuits filed \| lawsuit		1
ILLINOIS
Other Commitments [Line Items]
Income tax examination, number of lawsuits filed \| lawsuit		1
Minimum
Other Commitments [Line Items]
Estimated amount due \| $	$ 28.0
Estimated amount due, interest \| $	17.4
Estimated amount due, penalties (approximately) \| $	$ 0.3

PORTFOLIO LOANS - Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
PORTFOLIO LOANS - Narrative (Details) - USD ($)	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net deferred loan origination costs	$ 5,700,000		$ 7,000,000.0
Net accretable purchase accounting adjustments	(81,000,000.0)		(86,600,000)
Portfolio loans, net	13,290,836,000		13,393,776,000
Amount of interest collected and recognized on a cash basis	600,000	$ 0
Commitment to lend	15,100,000		13,500,000
Collateral dependent loans secured by real estate or business assets	41,800,000		47,800,000
Other repossessed assets	3,200,000
Loans in the process of foreclosure	1,200,000
90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross interest income that would have been recorded if impaired loans had been current	1,100,000	200,000
Bank Overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans, net	6,100,000		$ 7,100,000
Retail loans \| CRE and Retail real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans purchased	0	$ 0
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other repossessed assets	100,000
Commercial loans \| Watch
Accounts, Notes, Loans and Financing Receivable [Line Items]
Limit above which loans are annually reviewed	2,000,000.0
Commercial loans \| Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Limit above which loans are annually reviewed	350,000
Commercial loans \| Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Limit where loans are processed through an expedited underwriting process	$ 2,000,000.0

FAIR VALUE MEASUREMENTS - Schedule of Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Financial assets
Debt securities held to maturity	$ 601,074	$ 625,957
Restricted bank stock	81,722	77,006
Portfolio loans, net	13,290,836	13,393,776
Financial liabilities
Junior subordinated debt owed to unconsolidated trusts	77,400	77,328
Level 1 Inputs \| Carrying Amount
Financial assets
Cash and cash equivalents	288,462	280,227
Level 1 Inputs \| Fair Value
Financial assets
Cash and cash equivalents	288,462	280,227
Level 2 Inputs \| Carrying Amount
Financial assets
Interest-bearing time deposits in other banks	13,725	13,825
Debt securities held to maturity	725,540	746,385
Loans held for sale	5,224	5,752
Restricted bank stock	81,722	77,006
Accrued interest receivable	73,110	71,788
Financial liabilities
Time deposits	2,366,141	2,429,890
Securities sold under agreements to repurchase	156,364	166,929
Short-term borrowings	170,000	0
Junior subordinated debt owed to unconsolidated trusts	77,400	77,328
Accrued interest payable	26,186	25,372
Level 2 Inputs \| Carrying Amount \| Long-term borrowings
Financial liabilities
Long-term borrowings	123,466	113,806
Level 2 Inputs \| Fair Value
Financial assets
Interest-bearing time deposits in other banks	11,791	11,880
Debt securities held to maturity	601,074	625,957
Loans held for sale	5,255	5,886
Restricted bank stock	81,722	77,006
Accrued interest receivable	73,110	71,788
Financial liabilities
Time deposits	2,358,640	2,425,290
Securities sold under agreements to repurchase	156,364	166,929
Short-term borrowings	170,000	0
Junior subordinated debt owed to unconsolidated trusts	73,037	71,407
Accrued interest payable	26,186	25,372
Level 2 Inputs \| Fair Value \| Long-term borrowings
Financial liabilities
Long-term borrowings	122,835	113,853
Level 3 Inputs \| Carrying Amount
Financial assets
Portfolio loans, net	13,290,836	13,393,776
Mortgage servicing rights	1,577	1,459
Other servicing rights	2,086	2,086
Level 3 Inputs \| Carrying Amount \| Subordinated Debt
Financial liabilities
Long-term borrowings	99,499	99,395
Level 3 Inputs \| Fair Value
Financial assets
Portfolio loans, net	13,356,367	13,472,907
Mortgage servicing rights	5,239	5,176
Other servicing rights	2,265	2,193
Level 3 Inputs \| Fair Value \| Subordinated Debt
Financial liabilities
Long-term borrowings	$ 96,750	$ 94,500

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2026
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

DEBT SECURITIES - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Total pledged loans
Financial Instruments Owned and Pledged as Collateral [Line Items]
Debt securities, carrying amount	$ 723.0	$ 744.2

DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Financial Instruments Owned and Pledged as Collateral (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Cash pledged to secure obligations under derivative contracts
Derivative [Line Items]
Cash pledged to secure obligations	$ 14,400	$ 14,400
Collateral held to secure obligations under derivative contracts
Derivative [Line Items]
Cash pledged to secure obligations	$ 6,750	$ 5,050

- Definition

Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

+ References + Details

BUSINESS COMBINATIONS - Schedule of Reconciliation Between the Purchase Price and the Fair Value (Details) - CrossFirst $ in Thousands	Mar. 01, 2025 USD ($)
PCD Financial Assets
Gross contractual receivable for PCD financial assets	$ 4,790,000
Fair value of PCD financial assets	4,700,000
Financial Asset Acquired with Credit Deterioration
PCD Financial Assets
Gross contractual receivable for PCD financial assets	1,539,718
ACL recorded for estimated uncollectible contractual cash flows specific to PCD financial assets	(100,783)
Interest premium (discount) specific to PCD financial assets	(3,063)
Loans previously charged-off prior to acquisition	(110,740)
Fair value of PCD financial assets	$ 1,325,132

REGULATORY CAPITAL (Tables)

3 Months Ended

Mar. 31, 2026

Banking and Thrift, Other Disclosure [Abstract]

Schedule of Regulatory Capital Requirements Applicable to Busey and Busey Bank

The following tables summarize regulatory capital requirements applicable to First Busey and Busey Bank:


	As of March 31, 2026
	Actual				Minimum Capital Requirement				Minimum To Be Well Capitalized
(dollars in thousands)	Amount		Ratio		Amount		Ratio		Amount		Ratio
Common equity Tier 1 capital to risk weighted assets
First Busey	$	1,880,068	12.31	%	$	687,386	4.50	%	$	992,892	6.50	%
Busey Bank	$	2,144,335	14.06	%	$	686,292	4.50	%	$	991,311	6.50	%

Tier 1 capital to risk weighted assets
First Busey	$	2,102,818	13.77	%	$	916,515	6.00	%	$	1,222,020	8.00	%
Busey Bank	$	2,144,335	14.06	%	$	915,057	6.00	%	$	1,220,075	8.00	%

Total capital to risk weighted assets
First Busey	$	2,423,843	15.87	%	$	1,222,020	8.00	%	$	1,527,525	10.00	%
Busey Bank	$	2,285,782	14.99	%	$	1,220,075	8.00	%	$	1,525,094	10.00	%

Leverage ratio of Tier 1 capital to average assets
First Busey	$	2,102,818	11.88	%	$	708,101	4.00	%	N/A		N/A
Busey Bank	$	2,144,335	12.14	%	$	706,482	4.00	%	$	883,103	5.00	%


	As of December 31, 2025
	Actual				Minimum Capital Requirement				Minimum To Be Well Capitalized
(dollars in thousands)	Amount		Ratio		Amount		Ratio		Amount		Ratio
Common equity Tier 1 capital to risk weighted assets
First Busey	$	1,920,388	12.43	%	$	694,987	4.50	%	$	1,003,870	6.50	%
Busey Bank	$	2,150,048	13.97	%	$	692,654	4.50	%	$	1,000,500	6.50	%

Tier 1 capital to risk weighted assets
First Busey	$	2,143,138	13.88	%	$	926,650	6.00	%	$	1,235,533	8.00	%
Busey Bank	$	2,150,048	13.97	%	$	923,539	6.00	%	$	1,231,385	8.00	%

Total capital to risk weighted assets
First Busey	$	2,459,847	15.93	%	$	1,235,533	8.00	%	$	1,544,416	10.00	%
Busey Bank	$	2,287,179	14.86	%	$	1,231,385	8.00	%	$	1,539,231	10.00	%

Leverage ratio of Tier 1 capital to average assets
First Busey	$	2,143,138	11.93	%	$	718,334	4.00	%	N/A		N/A
Busey Bank	$	2,150,048	12.00	%	$	716,476	4.00	%	$	895,596	5.00	%

STOCK-BASED COMPENSATION - Schedule of Unamortized Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2026	Dec. 31, 2025
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unamortized stock-based compensation	$ 9,873	$ 15,309
Busey Awards \| 2020 Equity Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Weighted average period over which expense is to be recognized on awards issued under Busey's 2020 Equity Plan	1 year 10 months 24 days	1 year 9 months 18 days
CrossFirst Awards
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Weighted average period over which expense is to be recognized on awards issued under Busey's 2020 Equity Plan	1 year 1 month 6 days	1 year 2 months 12 days

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Thousands		3 Months Ended
	Apr. 30, 2026 USD ($)	Mar. 31, 2026 USD ($) segment	Dec. 31, 2025 USD ($)
Debt Instrument [Line Items]
Total assets		$ 18,036,622	$ 18,104,736
Number of operating segments \| segment		3
Number of reportable segments \| segment		3
Customer assets held in trust		$ 15,650,000	$ 15,660,000
Revolving Credit Facility
Debt Instrument [Line Items]
Floating interest rate margin (as a percent)		1.80%
Subsequent Event \| Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit maximum borrowing capacity	$ 50,000
Floating interest rate margin (as a percent)	1.65%
Collateral Pledged \| Derivative
Debt Instrument [Line Items]
Restricted cash and cash equivalents		$ 14,400
Third-Party Service Provider
Debt Instrument [Line Items]
Restricted cash and cash equivalents		13,600
Federal Reserve Bank
Debt Instrument [Line Items]
Restricted cash		$ 68,100

SIGNIFICANT ACCOUNTING POLICIES - Schedule of Stock Issuances (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)	$ 0.001		$ 0.001
Preferred stock, shares authorized (in shares)	1,000,000		1,000,000
Preferred stock, shares issued (in shares)	222,750		222,750
Preferred shares outstanding (in shares)	222,750		222,750
Preferred stock, value, issued	$ 0		$ 0
Series A Non-Cumulative Perpetual Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)	7,750		7,750
Preferred stock, shares issued (in shares)	7,750		7,750
Preferred shares outstanding (in shares)	7,750		7,750
Preferred stock, value, issued	$ 7.75		$ 7.75
Preferred stock, value, outstanding	7.75		$ 7.75
Issuance of preferred stock, net of issuance costs	$ 0	$ 7.75
8.25% Fixed-Rate Series B Non-Cumulative Perpetual Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate	8.25%		8.25%
Preferred stock, shares authorized (in shares)	230,000		230,000
Preferred stock, shares issued (in shares)	215,000		215,000
Preferred shares outstanding (in shares)	215,000		215,000
Preferred stock, value, issued	$ 215.00		$ 215.00
Preferred stock, value, outstanding	215.00		$ 215.00
Issuance of preferred stock, net of issuance costs	$ 0

TAX CREDIT INVESTMENTS AND OTHER INVESTMENTS IN UNCONSOLIDATED ENTITIES (Tables)

3 Months Ended

Mar. 31, 2026

Investments, All Other Investments [Abstract]

Schedule of Investments


		As of
(dollars in thousands)	Location	March 31, 2026		December 31, 2025
Investments in unconsolidated entities
Tax credit investments	Other assets	$	129,282	$	119,634
Other investments in unconsolidated entities	Other assets	46,314		46,361
Investments in unconsolidated entities		$	175,596	$	165,995

Unfunded investment obligations	Other liabilities	$	71,479	$	68,690

Actual amounts of income tax credits and other benefits, along with the investment amortization, are presented in the table below:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Income tax credits and other tax benefits		$	4,925	$	4,589
Amortization of investments in tax-advantaged projects		4,432		4,108

STOCK-BASED COMPENSATION - Schedule of Options and SSARs (Details) - shares	3 Months Ended
	Mar. 31, 2026	Dec. 31, 2025
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at beginning of year (in shares)	15,106
Exercised (in shares)	(5,280)
Forfeited (in shares)	0
Expired (in shares)	0
Outstanding at end of year (in shares)	9,826
Exercisable at end of year (in shares)	9,826
SSARs
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding at beginning of year (in shares)	136,295	270,398
Exercised (in shares)	(134,103)
Forfeited (in shares)	0
Expired (in shares)	0
Outstanding at end of year (in shares)	136,295
Exercisable at end of year (in shares)	119,457

LEASES - Narrative (Details) $ in Millions	Mar. 31, 2026 USD ($) lease
Leases [Abstract]
Leases not yet commenced commitments \| $	$ 1.7
Number of leases not yet commenced \| lease	1

PORTFOLIO LOANS - Schedule of Loan Modifications for Borrowers Experiencing Financial Difficulty (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Payment Deferral
Loans identified as impaired
Amortized cost basis	$ 2,215	$ 10,832
Payment Deferral \| Commercial loans \| C&I and other commercial
Loans identified as impaired
Amortized cost basis	2,215	10,832
Payment Deferral \| Commercial loans \| CRE and Retail real estate
Loans identified as impaired
Amortized cost basis		0
Payment Deferral \| Commercial loans \| Real estate construction
Loans identified as impaired
Amortized cost basis		0
Term Extension
Loans identified as impaired
Amortized cost basis	34,349	31,850
Term Extension \| Commercial loans \| C&I and other commercial
Loans identified as impaired
Amortized cost basis	$ 34,349	21,923
Term Extension \| Commercial loans \| CRE and Retail real estate
Loans identified as impaired
Amortized cost basis		4,719
Term Extension \| Commercial loans \| Real estate construction
Loans identified as impaired
Amortized cost basis		$ 5,208
Payment Deferral And Extended Maturity
Loans identified as impaired
% of total class of financing receivable	0.30%	0.30%
Payment Deferral And Extended Maturity \| Commercial loans \| C&I and other commercial
Loans identified as impaired
% of total class of financing receivable	0.90%	0.70%
Payment Deferral And Extended Maturity \| Commercial loans \| CRE and Retail real estate
Loans identified as impaired
% of total class of financing receivable		0.10%
Payment Deferral And Extended Maturity \| Commercial loans \| Real estate construction
Loans identified as impaired
% of total class of financing receivable		0.50%

DEPOSITS (Tables)

3 Months Ended

Mar. 31, 2026

Deposits [Abstract]

Schedule of Composition of Deposits

The composition of Busey’s deposits is presented in the table below:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Deposits
Noninterest-bearing demand deposits	$	3,526,036	$	3,659,421
Interest-bearing transaction deposits	3,129,186		3,119,475
Saving deposits and money market deposits	5,714,697		5,697,172
Time deposits	2,366,141		2,429,890
Total deposits	$	14,736,060	$	14,905,958

Additional information about Busey’s deposits is presented in the table below:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Brokered interest-bearing transaction deposits	$	50,119	$	50,136
Brokered savings deposits and money market deposits	10,004		10,000
Brokered time deposits	—		10,004
Aggregate amount of time deposits with a minimum denomination of $100,000	1,637,485		1,674,862
Aggregate amount of time deposits with a minimum denomination that meets or exceeds the FDIC insurance limit of $250,000	865,493		876,207

Schedule of Maturities of Time Deposits

Scheduled maturities of time deposits are presented in the table below:


(dollars in thousands)	As of March 31, 2026
Time deposits by schedule of maturities
Remainder of 2026	$	2,065,390
2027	279,010
2028	12,813
2029	4,665
2030	3,009
2031	1,244
Thereafter	10
Time deposits	$	2,366,141

DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Mortgage Banking Derivatives (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Interest rate lock commitments
Mortgage banking derivative assets
Derivative asset, statement of financial position [Extensible Enumeration]	Other assets	Other assets
Notional Amount	$ 3,139	$ 6,159
Fair value recorded in other assets	$ 42	$ 145
Forward sales commitments
Mortgage banking derivative assets
Derivative asset, statement of financial position [Extensible Enumeration]	Other assets	Other assets
Notional Amount	$ 6,861	$ 1,520
Fair value recorded in other assets	$ 70	$ 2
Mortgage banking derivative liabilities
Derivative liability, statement of financial position [Extensible Enumeration]	Other liabilities	Other liabilities
Notional Amount	$ 201	$ 9,278
Fair value recorded in other liabilities	0	26
Mortgage banking derivative assets \| Designated as Hedging Instrument
Mortgage banking derivative assets
Notional Amount	10,000	7,679
Fair value recorded in other assets	112	147
Mortgage banking derivative liabilities
Notional Amount	201	9,278
Fair value recorded in other liabilities	$ 0	$ 26

BORROWINGS - Schedule of Unamortized Debt Issuance Cost (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Debt Disclosure [Abstract]
Unamortized debt issuance costs	$ 501	$ 605

LEASES (Tables)

3 Months Ended

Mar. 31, 2026

Leases [Abstract]

Schedule of Lease-Related Balances

The following table summarizes lease-related balances that Busey reported on its Consolidated Balance Sheets (Unaudited):


		As of
(dollars in thousands)	Location	March 31, 2026		December 31, 2025
Lease balances
Right of use assets:
Operating leases	Other assets	$	32,104	$	30,204
Finance leases1	Premises and equipment, net	5,076		5,155
Total right of use assets		$	37,180	$	35,359

Lease liabilities:
Operating leases	Other liabilities	$	35,749	$	32,597
Finance leases	Long-term borrowings	6,178		6,223
Total lease liabilities		$	41,927	$	38,820

___________________________________________

1.Balances are presented net of accumulated amortization of $0.3 million and $0.3 million at March 31, 2026, and December 31, 2025, respectively.

Lease terms are summarized as follows:

As of

March 31,
2026

December 31,
2025

Lease terms

Weighted average remaining lease terms:

Operating leases

7.56 years

7.41 years

Finance leases

16.01 years

16.26 years

Weighted average discount rates:

Operating leases

4.28

4.24

Finance leases

5.10

Schedule of Lease Costs and Other Lease Information

The following table presents lease costs that Busey reported on its Consolidated Statements of Income (Unaudited):


		Three Months Ended March 31,
(dollars in thousands)	Location		2026		2025
Lease costs
Operating lease costs:
Premises rent expense	Net occupancy expense of premises		$	1,711	$	950
Equipment rent expense	Furniture and equipment expenses		8		7
Finance lease costs:
Amortization expense	Net occupancy expense of premises		79		—
Interest expense	Long-term borrowings		78		—
Variable lease costs	Net occupancy expense of premises		10		15
Short-term lease costs	Net occupancy expense of premises		5		12
Total lease cost			$	1,891	$	984

Cash paid for amounts included in the measurement of lease liabilities is presented in the following table:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Cash flows related to leases
Operating cash flows from operating leases		$	3,005	$	1,559
Operating cash flows from finance leases		78		—
Financing cash flows from finance leases		45		—

Right of use assets obtained in exchange for operating lease liabilities1		3,248		30,733

___________________________________________

1.The three months ended March 31, 2025, included $30.7 million right of use assets recognized in connection with the acquisition of CrossFirst.

Schedule of Future Undiscounted Lease Payments

Future undiscounted payments for leases with initial terms of one year or more are presented in the table below:


	As of March 31, 2026
(dollars in thousands)	Operating Leases		Finance Leases
Rent commitments
Remainder of 2026	$	5,091	$	368
2027	6,470		527
2028	5,941		540
2029	4,958		540
2030	4,057		540
2031	3,898		540
Thereafter	11,648		6,085
Total undiscounted cash flows	42,063		9,140
Less: Amounts representing interest	6,314		2,962
Present value of net future minimum lease payments	$	35,749	$	6,178

Schedule of Revenue Recorded in Connection with Leases

Revenues recorded in connection with these leases, reported in other income on Busey’s Consolidated Statements of Income (Unaudited), are summarized in the table below:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Rental income		$	214	$	216

Schedule of Future Minimum Lease Payments

Under the terms of these lease agreements, Busey is entitled to receive aggregate future lease payments as shown in the table below:


(dollars in thousands)	As of March 31, 2026
Rents to be received
Remainder of 2026	$	587
2027	515
2028	377
2029	197
2030	117


Total lease payments from operating leases	$	1,793

LEASES

3 Months Ended

Mar. 31, 2026

Leases [Abstract]

LEASES

NOTE 5. LEASES

Busey as the Lessee

Busey’s leases consist primarily of real estate leases for banking centers, ATM locations, and office space, as well as equipment leases. The following table summarizes lease-related balances that Busey reported on its Consolidated Balance Sheets (Unaudited):


		As of
(dollars in thousands)	Location	March 31, 2026		December 31, 2025
Lease balances
Right of use assets:
Operating leases	Other assets	$	32,104	$	30,204
Finance leases1	Premises and equipment, net	5,076		5,155
Total right of use assets		$	37,180	$	35,359

Lease liabilities:
Operating leases	Other liabilities	$	35,749	$	32,597
Finance leases	Long-term borrowings	6,178		6,223
Total lease liabilities		$	41,927	$	38,820

___________________________________________

1.Balances are presented net of accumulated amortization of $0.3 million and $0.3 million at March 31, 2026, and December 31, 2025, respectively.

Lease terms are summarized as follows:

As of

March 31,
2026

December 31,
2025

Lease terms

Weighted average remaining lease terms:

Operating leases

7.56 years

7.41 years

Finance leases

16.01 years

16.26 years

Weighted average discount rates:

Operating leases

4.28

4.24

Finance leases

5.10

The following table presents lease costs that Busey reported on its Consolidated Statements of Income (Unaudited):


		Three Months Ended March 31,
(dollars in thousands)	Location		2026		2025
Lease costs
Operating lease costs:
Premises rent expense	Net occupancy expense of premises		$	1,711	$	950
Equipment rent expense	Furniture and equipment expenses		8		7
Finance lease costs:
Amortization expense	Net occupancy expense of premises		79		—
Interest expense	Long-term borrowings		78		—
Variable lease costs	Net occupancy expense of premises		10		15
Short-term lease costs	Net occupancy expense of premises		5		12
Total lease cost			$	1,891	$	984

Cash paid for amounts included in the measurement of lease liabilities is presented in the following table:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Cash flows related to leases
Operating cash flows from operating leases		$	3,005	$	1,559
Operating cash flows from finance leases		78		—
Financing cash flows from finance leases		45		—

Right of use assets obtained in exchange for operating lease liabilities1		3,248		30,733

___________________________________________

1.The three months ended March 31, 2025, included $30.7 million right of use assets recognized in connection with the acquisition of CrossFirst.

Future undiscounted payments for leases with initial terms of one year or more are presented in the table below:


	As of March 31, 2026
(dollars in thousands)	Operating Leases		Finance Leases
Rent commitments
Remainder of 2026	$	5,091	$	368
2027	6,470		527
2028	5,941		540
2029	4,958		540
2030	4,057		540
2031	3,898		540
Thereafter	11,648		6,085
Total undiscounted cash flows	42,063		9,140
Less: Amounts representing interest	6,314		2,962
Present value of net future minimum lease payments	$	35,749	$	6,178

As of March 31, 2026, Busey had commitments totaling $1.7 million for one lease contract with a future accounting commencement date.

Busey as the Lessor

Busey leases space to outside parties, consisting of operating leases primarily for offices and parking areas. Revenues recorded in connection with these leases, reported in other income on Busey’s Consolidated Statements of Income (Unaudited), are summarized in the table below:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Rental income		$	214	$	216

Noncancellable terms for these leases extend through 2030. Under the terms of these lease agreements, Busey is entitled to receive aggregate future lease payments as shown in the table below:


(dollars in thousands)	As of March 31, 2026
Rents to be received
Remainder of 2026	$	587
2027	515
2028	377
2029	197
2030	117


Total lease payments from operating leases	$	1,793

LEASES

NOTE 5. LEASES

Busey as the Lessee


		As of
(dollars in thousands)	Location	March 31, 2026		December 31, 2025
Lease balances
Right of use assets:
Operating leases	Other assets	$	32,104	$	30,204
Finance leases1	Premises and equipment, net	5,076		5,155
Total right of use assets		$	37,180	$	35,359

Lease liabilities:
Operating leases	Other liabilities	$	35,749	$	32,597
Finance leases	Long-term borrowings	6,178		6,223
Total lease liabilities		$	41,927	$	38,820

___________________________________________

1.Balances are presented net of accumulated amortization of $0.3 million and $0.3 million at March 31, 2026, and December 31, 2025, respectively.

Lease terms are summarized as follows:

As of

March 31,
2026

December 31,
2025

Lease terms

Weighted average remaining lease terms:

Operating leases

7.56 years

7.41 years

Finance leases

16.01 years

16.26 years

Weighted average discount rates:

Operating leases

4.28

4.24

Finance leases

5.10

The following table presents lease costs that Busey reported on its Consolidated Statements of Income (Unaudited):


		Three Months Ended March 31,
(dollars in thousands)	Location		2026		2025
Lease costs
Operating lease costs:
Premises rent expense	Net occupancy expense of premises		$	1,711	$	950
Equipment rent expense	Furniture and equipment expenses		8		7
Finance lease costs:
Amortization expense	Net occupancy expense of premises		79		—
Interest expense	Long-term borrowings		78		—
Variable lease costs	Net occupancy expense of premises		10		15
Short-term lease costs	Net occupancy expense of premises		5		12
Total lease cost			$	1,891	$	984

Cash paid for amounts included in the measurement of lease liabilities is presented in the following table:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Cash flows related to leases
Operating cash flows from operating leases		$	3,005	$	1,559
Operating cash flows from finance leases		78		—
Financing cash flows from finance leases		45		—

Right of use assets obtained in exchange for operating lease liabilities1		3,248		30,733

___________________________________________

1.The three months ended March 31, 2025, included $30.7 million right of use assets recognized in connection with the acquisition of CrossFirst.

Future undiscounted payments for leases with initial terms of one year or more are presented in the table below:


	As of March 31, 2026
(dollars in thousands)	Operating Leases		Finance Leases
Rent commitments
Remainder of 2026	$	5,091	$	368
2027	6,470		527
2028	5,941		540
2029	4,958		540
2030	4,057		540
2031	3,898		540
Thereafter	11,648		6,085
Total undiscounted cash flows	42,063		9,140
Less: Amounts representing interest	6,314		2,962
Present value of net future minimum lease payments	$	35,749	$	6,178

As of March 31, 2026, Busey had commitments totaling $1.7 million for one lease contract with a future accounting commencement date.

Busey as the Lessor


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Rental income		$	214	$	216

Noncancellable terms for these leases extend through 2030. Under the terms of these lease agreements, Busey is entitled to receive aggregate future lease payments as shown in the table below:


(dollars in thousands)	As of March 31, 2026
Rents to be received
Remainder of 2026	$	587
2027	515
2028	377
2029	197
2030	117


Total lease payments from operating leases	$	1,793

BORROWINGS - Revolving Line of Credit (Details) - Revolving Credit Facility - USD ($)		3 Months Ended
	Apr. 30, 2026	Mar. 31, 2026
Short-Term Debt [Line Items]
Issuance of debt		$ 40,000,000.0
Floating interest rate margin (as a percent)		1.80%
Balance outstanding		$ 0
Subsequent Event
Short-Term Debt [Line Items]
Floating interest rate margin (as a percent)	1.65%
Line of credit maximum borrowing capacity	$ 50,000,000.0

PORTFOLIO LOANS - Schedule of Prior Year Risk Grades of Portfolio Loans, Further Sorted by Origination (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2026	Dec. 31, 2025
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	$ 862,458	$ 2,775,707
2024	2,479,439	1,552,638
2023	1,426,704	1,762,494
2022	1,608,732	2,087,139
2021	1,939,138	1,612,675
Prior	2,615,912	1,277,588
Revolving Loans	2,527,507	2,499,558
Total	13,459,890	13,567,799
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2025, charge-off	292	7,674
2024, charge-off	104	14,536
2023, charge-off	0	4,617
2022, charge -off	267	1,497
2021, charge-off	6,180	13,844
Prior, charge-off	743	11,581
Revolving Loans, charge-off	254	5,893
Total, gross write-offs	7,840	59,642
Commercial loans
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	10,743,286	10,818,515
Commercial loans \| C&I and other commercial
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	203,555	886,826
2024	768,638	582,244
2023	544,736	476,569
2022	401,969	297,050
2021	266,469	243,208
Prior	317,293	148,697
Revolving Loans	1,622,077	1,594,614
Total	4,124,737	4,229,208
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2025, charge-off	50	4,667
2024, charge-off	104	3,332
2023, charge-off	0	4,347
2022, charge -off	257	1,450
2021, charge-off	6,180	13,591
Prior, charge-off	743	11,456
Revolving Loans, charge-off	171	5,716
Total, gross write-offs	7,505	44,559
Commercial loans \| C&I and other commercial \| Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	176,684	833,539
2024	703,182	486,278
2023	444,948	342,560
2022	281,266	207,053
2021	190,104	178,429
Prior	247,451	122,904
Revolving Loans	1,356,182	1,396,826
Total	3,399,817	3,567,589
Commercial loans \| C&I and other commercial \| Watch
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	5,980	21,750
2024	37,677	79,853
2023	79,414	56,387
2022	54,522	38,786
2021	30,451	48,624
Prior	48,220	16,778
Revolving Loans	164,690	112,935
Total	420,954	375,113
Commercial loans \| C&I and other commercial \| Special Mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	6,657	21,712
2024	18,453	11,609
2023	12,256	56,578
2022	19,335	26,343
2021	21,324	5,339
Prior	6,427	800
Revolving Loans	61,112	54,433
Total	145,564	176,814
Commercial loans \| C&I and other commercial \| Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	14,231	8,336
2024	4,942	605
2023	4,800	20,444
2022	45,663	14,603
2021	20,228	9,868
Prior	9,753	3,655
Revolving Loans	27,108	17,883
Total	126,725	75,394
Commercial loans \| C&I and other commercial \| Substandard Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	3	1,489
2024	4,384	3,899
2023	3,318	600
2022	1,183	10,265
2021	4,362	948
Prior	5,442	4,560
Revolving Loans	12,985	12,537
Total	31,677	34,298
Commercial loans \| CRE and Retail real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	496,155	1,339,978
2024	1,158,719	569,197
2023	507,028	841,829
2022	823,939	1,197,182
2021	1,094,074	941,492
Prior	1,437,307	612,815
Revolving Loans	48,822	47,525
Total	5,566,044	5,550,018
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2025, charge-off	0	1,297
2024, charge-off	0	11,057
2023, charge-off	0	0
2022, charge -off	0	0
2021, charge-off	0	253
Prior, charge-off	0	0
Revolving Loans, charge-off	0	0
Total, gross write-offs	0	12,607
Commercial loans \| CRE and Retail real estate \| Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	374,592	1,077,169
2024	970,541	483,950
2023	445,815	710,448
2022	660,590	1,035,426
2021	934,154	740,680
Prior	1,183,257	515,631
Revolving Loans	45,082	43,830
Total	4,614,031	4,607,134
Commercial loans \| CRE and Retail real estate \| Watch
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	100,410	210,673
2024	131,248	61,926
2023	55,151	119,986
2022	126,753	143,072
2021	139,092	161,387
Prior	193,822	69,789
Revolving Loans	2,794	2,572
Total	749,270	769,405
Commercial loans \| CRE and Retail real estate \| Special Mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	19,919	49,648
2024	54,289	22,642
2023	5,388	2,991
2022	27,987	13,811
2021	16,485	32,109
Prior	44,198	18,858
Revolving Loans	731	908
Total	168,997	140,967
Commercial loans \| CRE and Retail real estate \| Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	1,234	2,416
2024	2,122	679
2023	421	3,857
2022	3,243	4,873
2021	3,860	7,316
Prior	12,184	5,324
Revolving Loans	215	215
Total	23,279	24,680
Commercial loans \| CRE and Retail real estate \| Substandard Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	0	72
2024	519	0
2023	253	4,547
2022	5,366	0
2021	483	0
Prior	3,846	3,213
Revolving Loans	0	0
Total	10,467	7,832
Commercial loans \| Real estate construction
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	115,960	447,571
2024	405,560	270,502
2023	251,507	111,929
2022	71,932	112,234
2021	111,876	12,862
Prior	14,866	2,733
Revolving Loans	80,804	81,458
Total	1,052,505	1,039,289
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2025, charge-off	0	0
2024, charge-off	0	0
2023, charge-off	0	0
2022, charge -off	0	0
2021, charge-off	0	0
Prior, charge-off	0	0
Revolving Loans, charge-off	0	0
Total, gross write-offs	0	0
Commercial loans \| Real estate construction \| Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	102,064	395,019
2024	373,586	268,117
2023	251,234	107,930
2022	69,954	89,673
2021	69,315	5,356
Prior	7,516	2,733
Revolving Loans	74,606	74,237
Total	948,275	943,065
Commercial loans \| Real estate construction \| Watch
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	13,896	18,571
2024	2,153	2,112
2023	0	3,999
2022	1,978	22,561
2021	42,561	167
Prior	160	0
Revolving Loans	6,198	7,221
Total	66,946	54,631
Commercial loans \| Real estate construction \| Special Mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	0	17,961
2024	18,945	0
2023	0	0
2022	0	0
2021	0	6,573
Prior	6,434	0
Revolving Loans	0	0
Total	25,379	24,534
Commercial loans \| Real estate construction \| Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	0	16,020
2024	10,876	0
2023	0	0
2022	0	0
2021	0	766
Prior	756	0
Revolving Loans	0	0
Total	11,632	16,786
Commercial loans \| Real estate construction \| Substandard Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	0	0
2024	0	273
2023	273	0
2022	0	0
2021	0	0
Prior	0	0
Revolving Loans	0	0
Total	273	273
Retail loans
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	2,716,604	2,749,284
Retail loans \| CRE and Retail real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	46,038	96,099
2024	141,672	128,430
2023	121,544	298,742
2022	281,637	450,218
2021	439,711	410,552
Prior	841,201	512,458
Revolving Loans	247,818	258,117
Total	2,119,621	2,154,616
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2025, charge-off	70	1,164
2024, charge-off	0	0
2023, charge-off	0	0
2022, charge -off	0	0
2021, charge-off	0	0
Prior, charge-off	0	51
Revolving Loans, charge-off	81	36
Total, gross write-offs	151	1,251
Retail loans \| CRE and Retail real estate \| Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	45,952	93,212
2024	138,678	127,475
2023	120,634	269,877
2022	252,430	446,309
2021	436,101	407,851
Prior	836,870	508,504
Revolving Loans	246,306	252,987
Total	2,076,971	2,106,215
Retail loans \| CRE and Retail real estate \| Watch
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	86	2,686
2024	2,590	569
2023	530	24,601
2022	24,972	1,492
2021	1,464	267
Prior	512	482
Revolving Loans	545	577
Total	30,699	30,674
Retail loans \| CRE and Retail real estate \| Special Mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	0	47
2024	47	78
2023	72	4,028
2022	0	1,454
2021	1,432	1,686
Prior	1,661	0
Revolving Loans	207	214
Total	3,419	7,507
Retail loans \| CRE and Retail real estate \| Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	0	0
2024	0	0
2023	0	108
2022	4,108	440
2021	135	484
Prior	1,100	631
Revolving Loans	0	136
Total	5,343	1,799
Retail loans \| CRE and Retail real estate \| Substandard Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	0	154
2024	357	308
2023	308	128
2022	127	523
2021	579	264
Prior	1,058	2,841
Revolving Loans	760	4,203
Total	3,189	8,421
Retail loans \| Retail other
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	750	5,233
2024	4,850	2,265
2023	1,889	33,425
2022	29,255	30,455
2021	27,008	4,561
Prior	5,245	885
Revolving Loans	527,986	517,844
Total	596,983	594,668
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2025, charge-off	172	546
2024, charge-off	0	147
2023, charge-off	0	270
2022, charge -off	10	47
2021, charge-off	0	0
Prior, charge-off	0	74
Revolving Loans, charge-off	2	141
Total, gross write-offs	184	1,225
Retail loans \| Retail other \| Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	750	5,233
2024	4,850	2,265
2023	1,889	33,349
2022	29,179	30,321
2021	26,892	4,561
Prior	5,245	885
Revolving Loans	527,985	517,680
Total	596,790	594,294
Retail loans \| Retail other \| Substandard Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2025	0	0
2024	0	0
2023	0	76
2022	76	134
2021	116	0
Prior	0	0
Revolving Loans	1	164
Total	$ 193	$ 374

FAIR VALUE MEASUREMENTS - Schedule of Activity for Financial Assets Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Recurring - Level 3 Inputs - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ (35)	$ 5
Gains (losses) recognized in earnings	9	2
Sales	0	6
Assumed in business combinations	0	(41)
Ending Balance	(26)	(39)
CrossFirst
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Gains (losses) recognized in earnings	$ 0	$ (11)

BUSINESS COMBINATIONS - Schedule of Pre-tax Acquisition Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Business Combination [Line Items]
Pre-tax acquisition expenses	$ 5,244	$ 71,598
CrossFirst
Business Combination [Line Items]
Pre-tax acquisition expenses	5,244	71,490
M&M
Business Combination [Line Items]
Pre-tax acquisition expenses	$ 0	$ 108

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

PORTFOLIO LOANS - Schedule of Modified Loans with Subsequent Defaults (Details) - Term Extension $ in Thousands	3 Months Ended
	Mar. 31, 2026 USD ($)
Distributions of portfolio loans
Loans with Subsequent Defaults	$ 273
Commercial loans \| CRE and Retail real estate
Distributions of portfolio loans
Loans with Subsequent Defaults	$ 273

BUSINESS COMBINATIONS - Schedule of Pre-tax Costs to Consummate the Merger (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract]
Pre-tax costs to consummate the merger	$ 119	$ 7,144

STOCK-BASED COMPENSATION - Schedule of Changes in the Company's Stock Option Awards (Details)	3 Months Ended
	Mar. 31, 2026 shares
RSU Awards
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Non-vested at beginning of period (in shares)	1,320,537
Granted (in shares)	0
Dividend equivalents earned (in shares)	13,929
Vested (in shares)	(613,166)
Forfeited (in shares)	(58,395)
Non-vested at end of period (in shares)	662,905
Vested and outstanding at end of period (in shares)	0
PSU Awards
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Non-vested at beginning of period (in shares)	525,501
Granted (in shares)	0
Dividend equivalents earned (in shares)	1,877
Vested (in shares)	(43,283)
Forfeited (in shares)	(32,086)
Non-vested at end of period (in shares)	452,009
Vested and outstanding at end of period (in shares)	0
DSU Awards
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Non-vested at beginning of period (in shares)	41,218
Granted (in shares)	0
Dividend equivalents earned (in shares)	435
Vested (in shares)	(41,653)
Forfeited (in shares)	0
Non-vested at end of period (in shares)	0
Vested and outstanding at end of period (in shares)	189,269

PORTFOLIO LOANS - Schedule of Activity on the Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Activity in the allowance for loan losses
ACL beginning balance	$ 174,023	$ 83,404
Provision for loan losses	2,393	19
Day 1 PCD		100,783
Provision for loan losses and Day 2 Provision for loan losses	3,058	45,593
Charged-off	(7,840)	(31,835)
Recoveries	478	406
ACL ending balance	169,054	195,210
Charged-off	7,840	31,835
CrossFirst
Activity in the allowance for loan losses
Provision for loan losses and Day 2 Provision for loan losses		42,433
Charged-off		(29,600)
Charged-off		29,600
Commercial loans \| C&I and other commercial
Activity in the allowance for loan losses
ACL beginning balance	61,370	21,589
Provision for loan losses	3,556	623
Day 1 PCD		75,569
Charged-off	(7,505)	(31,221)
Recoveries	383	96
ACL ending balance	57,804	89,304
Charged-off	7,505	31,221
Commercial loans \| C&I and other commercial \| CrossFirst
Activity in the allowance for loan losses
Provision for loan losses and Day 2 Provision for loan losses		22,648
Commercial loans \| CRE and Retail real estate
Activity in the allowance for loan losses
ACL beginning balance	70,328	32,301
Provision for loan losses	(234)	(393)
Day 1 PCD		21,588
Charged-off	0	(253)
Recoveries	6	131
ACL ending balance	70,100	68,478
Charged-off	0	253
Commercial loans \| CRE and Retail real estate \| CrossFirst
Activity in the allowance for loan losses
Provision for loan losses and Day 2 Provision for loan losses		15,104
Commercial loans \| Real estate construction
Activity in the allowance for loan losses
ACL beginning balance	11,568	3,345
Provision for loan losses	1,019	311
Day 1 PCD		2,112
Charged-off	0	0
Recoveries	1	10
ACL ending balance	12,588	8,689
Charged-off	0	0
Commercial loans \| Real estate construction \| CrossFirst
Activity in the allowance for loan losses
Provision for loan losses and Day 2 Provision for loan losses		2,911
Retail loans \| CRE and Retail real estate
Activity in the allowance for loan losses
ACL beginning balance	29,178	23,711
Provision for loan losses	(1,944)	(503)
Day 1 PCD		1,430
Charged-off	(151)	0
Recoveries	57	133
ACL ending balance	27,140	26,399
Charged-off	151	0
Retail loans \| CRE and Retail real estate \| CrossFirst
Activity in the allowance for loan losses
Provision for loan losses and Day 2 Provision for loan losses		1,628
Retail loans \| Retail other
Activity in the allowance for loan losses
ACL beginning balance	1,579	2,458
Provision for loan losses	(4)	(19)
Day 1 PCD		84
Charged-off	(184)	(361)
Recoveries	31	36
ACL ending balance	1,422	2,340
Charged-off	$ 184	361
Retail loans \| Retail other \| CrossFirst
Activity in the allowance for loan losses
Provision for loan losses and Day 2 Provision for loan losses		$ 142

BORROWINGS - Short-term Borrowings (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Short-Term Debt [Line Items]
Total short-term borrowings	$ 170,000	$ 0
FHLB advances maturing in less than one year from date of origination, and the current portion of long-term FHLB advances due within 12 months
Short-Term Debt [Line Items]
Total short-term borrowings	$ 170,000	$ 0

REGULATORY CAPITAL (Details) $ in Thousands	Mar. 31, 2026 USD ($)	Dec. 31, 2025 USD ($)
Common Equity Tier 1 Capital to Risk Weighted Assets, Amount
Actual	$ 1,880,068	$ 1,920,388
Minimum Capital Requirement	687,386	694,987
Minimum To Be Well Capitalized	$ 992,892	$ 1,003,870
Common Equity Tier 1 Capital to Risk Weighted Assets, Ratio
Actual	0.1231	0.1243
Minimum Capital Requirement	0.0450	0.0450
Minimum To Be Well Capitalized	0.0650	0.0650
Tier 1 Capital to Risk Weighted Assets, Amount
Actual	$ 2,102,818	$ 2,143,138
Minimum Capital Requirement	916,515	926,650
Minimum To Be Well Capitalized	$ 1,222,020	$ 1,235,533
Tier 1 Capital to Risk Weighted Assets, Ratio
Actual	0.1377	0.1388
Minimum Capital Requirement	0.0600	0.0600
Minimum To Be Well Capitalized	0.0800	0.0800
Total Capital to Risk Weighted Assets, Amount
Actual	$ 2,423,843	$ 2,459,847
Minimum Capital Requirement	1,222,020	1,235,533
Minimum To Be Well Capitalized	$ 1,527,525	$ 1,544,416
Total Capital to Risk Weighted Assets, Ratio
Actual	0.1587	0.1593
Minimum Capital Requirement	0.0800	0.0800
Minimum To Be Well Capitalized	0.1000	0.1000
Leverage Ratio of Tier 1 Capital to Average Assets, Amount
Actual	$ 2,102,818	$ 2,143,138
Minimum Capital Requirement	$ 708,101	$ 718,334
Leverage Ratio of Tier 1 Capital to Average Assets, Ratio
Actual	0.1188	0.1193
Minimum Capital Requirement	0.0400	0.0400
Busey Bank
Common Equity Tier 1 Capital to Risk Weighted Assets, Amount
Actual	$ 2,144,335	$ 2,150,048
Minimum Capital Requirement	686,292	692,654
Minimum To Be Well Capitalized	$ 991,311	$ 1,000,500
Common Equity Tier 1 Capital to Risk Weighted Assets, Ratio
Actual	0.1406	0.1397
Minimum Capital Requirement	0.0450	0.0450
Minimum To Be Well Capitalized	0.0650	0.0650
Tier 1 Capital to Risk Weighted Assets, Amount
Actual	$ 2,144,335	$ 2,150,048
Minimum Capital Requirement	915,057	923,539
Minimum To Be Well Capitalized	$ 1,220,075	$ 1,231,385
Tier 1 Capital to Risk Weighted Assets, Ratio
Actual	0.1406	0.1397
Minimum Capital Requirement	0.0600	0.0600
Minimum To Be Well Capitalized	0.0800	0.0800
Total Capital to Risk Weighted Assets, Amount
Actual	$ 2,285,782	$ 2,287,179
Minimum Capital Requirement	1,220,075	1,231,385
Minimum To Be Well Capitalized	$ 1,525,094	$ 1,539,231
Total Capital to Risk Weighted Assets, Ratio
Actual	0.1499	0.1486
Minimum Capital Requirement	0.0800	0.0800
Minimum To Be Well Capitalized	0.1000	0.1000
Leverage Ratio of Tier 1 Capital to Average Assets, Amount
Actual	$ 2,144,335	$ 2,150,048
Minimum Capital Requirement	706,482	716,476
Minimum To Be Well Capitalized	$ 883,103	$ 895,596
Leverage Ratio of Tier 1 Capital to Average Assets, Ratio
Actual	0.1214	0.1200
Minimum Capital Requirement	0.0400	0.0400
Minimum To Be Well Capitalized	0.0500	0.0500

DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of the Interest-Rate Swaps Designated as Cash Flow Hedges (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Interest Rate Swap
Balances carried in AOCI
Unrealized gains (losses) on cash flow hedges, net of tax	$ 0	$ 0
Cash Flow Hedging \| Interest Rate Swap
Balances carried in AOCI
Unrealized gains (losses) on cash flow hedges, net of tax	(9,347)		$ (7,616)
Cash Flow Hedging \| Interest Rate Swap \| Other assets
Gross aggregate fair value of the swaps
Gross aggregate fair value of swap assets	1,776		3,215
Cash Flow Hedging \| Interest Rate Swap \| Other liabilities
Gross aggregate fair value of the swaps
Gross aggregate fair value of swap liabilities	15,421		14,589
Cash Flow Hedging \| Prime Loan Swap
Derivative [Line Items]
Notional amount	$ 300,000		$ 300,000
Weighted average rate: receive-fixed	4.81%		4.81%
Weighted average variable interest rates	6.75%		6.81%
Weighted average maturity	2 years 10 months 6 days		3 years 1 month 6 days
Cash Flow Hedging \| SOFR Loan Swaps
Derivative [Line Items]
Notional amount	$ 400,000		$ 200,000
Weighted average rate: receive-fixed	3.71%		3.78%
Weighted average variable interest rates	3.67%		3.82%
Weighted average maturity	5 years 2 months 4 days		3 years 9 months 3 days
Cash Flow Hedging \| Forward Starting SOFR Loan Swap
Derivative [Line Items]
Notional amount	$ 200,000

DEBT SECURITIES - Schedule of Additional Information on Debt Securities In Unrealized or Unrecognized Loss Position (Details) $ in Thousands	Mar. 31, 2026 USD ($) security	Dec. 31, 2025 USD ($) security
Available for Sale
Debt securities with gross unrealized or unrecognized losses, fair value \| $	$ 1,429,446	$ 1,131,224
Gross unrealized or unrecognized losses on debt securities \| $	$ 158,580	$ 152,182
Ratio of gross unrealized or unrecognized losses to debt securities with gross unrealized or unrecognized losses	11.10%	13.50%
Count of debt securities \| security	637	637
Count of debt securities in an unrealized or unrecognized loss position \| security	455	376
Held to Maturity
Debt securities with gross unrealized or unrecognized losses, fair value \| $	$ 601,074	$ 625,957
Gross unrealized or unrecognized losses on debt securities \| $	$ 124,466	$ 120,428
Ratio of gross unrealized or unrecognized losses to debt securities with gross unrealized or unrecognized losses	20.70%	19.20%
Count of debt securities \| security	52	52
Count of debt securities in an unrealized or unrecognized loss position \| security	52	52
Total
Debt securities with gross unrealized or unrecognized losses, fair value \| $	$ 2,030,520	$ 1,757,181
Gross unrealized or unrecognized losses on debt securities \| $	$ 283,046	$ 272,610
Ratio of gross unrealized or unrecognized losses to debt securities with gross unrealized or unrecognized losses	13.90%	15.50%
Count of debt securities \| security	689	689
Count of debt securities in an unrealized or unrecognized loss position \| security	507	428

REGULATORY CAPITAL

3 Months Ended

Mar. 31, 2026

Banking and Thrift, Other Disclosure [Abstract]

REGULATORY CAPITAL

NOTE 8. REGULATORY CAPITAL

First Busey and Busey Bank are subject to various regulatory capital requirements administered by federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory—and possibly additional discretionary—actions by regulators that, if undertaken, could have a direct material effect on First Busey's consolidated financial statements. Capital amounts and classification also are subject to qualitative judgments by regulators about components, risk weightings, and other factors.

Banking regulations identify five capital categories for insured depository institutions: well capitalized, adequately capitalized, undercapitalized, significantly undercapitalized, and critically undercapitalized. As of March 31, 2026, and December 31, 2025, all capital ratios of First Busey and Busey Bank exceeded well capitalized levels under the applicable regulatory capital adequacy guidelines. Management believes that no events or changes have occurred subsequent to March 31, 2026, that would change this designation.

Capital Amounts and Ratios

The following tables summarize regulatory capital requirements applicable to First Busey and Busey Bank:


	As of March 31, 2026
	Actual				Minimum Capital Requirement				Minimum To Be Well Capitalized
(dollars in thousands)	Amount		Ratio		Amount		Ratio		Amount		Ratio
Common equity Tier 1 capital to risk weighted assets
First Busey	$	1,880,068	12.31	%	$	687,386	4.50	%	$	992,892	6.50	%
Busey Bank	$	2,144,335	14.06	%	$	686,292	4.50	%	$	991,311	6.50	%

Tier 1 capital to risk weighted assets
First Busey	$	2,102,818	13.77	%	$	916,515	6.00	%	$	1,222,020	8.00	%
Busey Bank	$	2,144,335	14.06	%	$	915,057	6.00	%	$	1,220,075	8.00	%

Total capital to risk weighted assets
First Busey	$	2,423,843	15.87	%	$	1,222,020	8.00	%	$	1,527,525	10.00	%
Busey Bank	$	2,285,782	14.99	%	$	1,220,075	8.00	%	$	1,525,094	10.00	%

Leverage ratio of Tier 1 capital to average assets
First Busey	$	2,102,818	11.88	%	$	708,101	4.00	%	N/A		N/A
Busey Bank	$	2,144,335	12.14	%	$	706,482	4.00	%	$	883,103	5.00	%


	As of December 31, 2025
	Actual				Minimum Capital Requirement				Minimum To Be Well Capitalized
(dollars in thousands)	Amount		Ratio		Amount		Ratio		Amount		Ratio
Common equity Tier 1 capital to risk weighted assets
First Busey	$	1,920,388	12.43	%	$	694,987	4.50	%	$	1,003,870	6.50	%
Busey Bank	$	2,150,048	13.97	%	$	692,654	4.50	%	$	1,000,500	6.50	%

Tier 1 capital to risk weighted assets
First Busey	$	2,143,138	13.88	%	$	926,650	6.00	%	$	1,235,533	8.00	%
Busey Bank	$	2,150,048	13.97	%	$	923,539	6.00	%	$	1,231,385	8.00	%

Total capital to risk weighted assets
First Busey	$	2,459,847	15.93	%	$	1,235,533	8.00	%	$	1,544,416	10.00	%
Busey Bank	$	2,287,179	14.86	%	$	1,231,385	8.00	%	$	1,539,231	10.00	%

Leverage ratio of Tier 1 capital to average assets
First Busey	$	2,143,138	11.93	%	$	718,334	4.00	%	N/A		N/A
Busey Bank	$	2,150,048	12.00	%	$	716,476	4.00	%	$	895,596	5.00	%

Capital Conservation Buffer

In July 2013, U.S. federal banking authorities approved the Basel III Rule for strengthening international capital standards. The Basel III Rule introduced a capital conservation buffer, composed entirely of common equity Tier 1 capital, which is added to the minimum risk-weighted asset ratios. The capital conservation buffer is not a minimum capital requirement; however, banking institutions with a ratio of common equity Tier 1 capital to risk-weighted assets below the capital conservation buffer will face constraints on dividends, equity repurchases, and discretionary bonus payments based on the amount of the shortfall. In order to refrain from restrictions on dividends, equity repurchases, and discretionary bonus payments, banking institutions must maintain minimum ratios of (1) common equity Tier 1 capital to risk-weighted assets of at least 7.0%, (2) Tier 1 capital to risk-weighted assets of at least 8.5%, and (3) total capital to risk-weighted assets of at least 10.5%.

- Definition

The entire disclosure for regulatory capital requirement for depository and lending institutions. Institutions include, but not are not limited to, finance company, insured depository institution, bank holding company, savings and loan association holding company, bank and savings institution not federally insured, mortgage company, foreign financial institution and credit union.

+ References + Details

PORTFOLIO LOANS - Schedule of Past Due and Non-accrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Financing Receivable, Past Due [Line Items]
Total portfolio loans	$ 13,459,890	$ 13,567,799
90+ days past due and still accruing	812	2,288
Non-Accrual Loans	45,799	51,198
Non-Accrual Loans with No Allowance for Credit Losses	11,684	6,707
30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	12,754	9,009
60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	4,711	7,466
Commercial loans
Financing Receivable, Past Due [Line Items]
Total portfolio loans	10,743,286	10,818,515
90+ days past due and still accruing	518	2,128
Non-Accrual Loans	42,417	42,403
Non-Accrual Loans with No Allowance for Credit Losses	11,335	6,358
Commercial loans \| 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	5,371	4,061
Commercial loans \| 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	412	3,107
Commercial loans \| C&I and other commercial
Financing Receivable, Past Due [Line Items]
Total portfolio loans	4,124,737	4,229,208
90+ days past due and still accruing	518	2,128
Non-Accrual Loans	31,677	34,298
Non-Accrual Loans with No Allowance for Credit Losses	7,451	4,612
Commercial loans \| C&I and other commercial \| 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	2,828	3,577
Commercial loans \| C&I and other commercial \| 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	412	593
Commercial loans \| CRE and Retail real estate
Financing Receivable, Past Due [Line Items]
Total portfolio loans	5,566,044	5,550,018
90+ days past due and still accruing	0	0
Non-Accrual Loans	10,467	7,832
Non-Accrual Loans with No Allowance for Credit Losses	3,726	1,588
Commercial loans \| CRE and Retail real estate \| 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	2,195	484
Commercial loans \| CRE and Retail real estate \| 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	0	2,514
Commercial loans \| Real estate construction
Financing Receivable, Past Due [Line Items]
Total portfolio loans	1,052,505	1,039,289
90+ days past due and still accruing	0	0
Non-Accrual Loans	273	273
Non-Accrual Loans with No Allowance for Credit Losses	158	158
Commercial loans \| Real estate construction \| 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	348	0
Commercial loans \| Real estate construction \| 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	0	0
Retail loans
Financing Receivable, Past Due [Line Items]
Total portfolio loans	2,716,604	2,749,284
90+ days past due and still accruing	294	160
Non-Accrual Loans	3,382	8,795
Non-Accrual Loans with No Allowance for Credit Losses	349	349
Retail loans \| 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	7,383	4,948
Retail loans \| 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	4,299	4,359
Retail loans \| CRE and Retail real estate
Financing Receivable, Past Due [Line Items]
Total portfolio loans	2,119,621	2,154,616
90+ days past due and still accruing	0	136
Non-Accrual Loans	3,189	8,421
Non-Accrual Loans with No Allowance for Credit Losses	349	349
Retail loans \| CRE and Retail real estate \| 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	3,093	2,457
Retail loans \| CRE and Retail real estate \| 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	4,269	4,280
Retail loans \| Retail other
Financing Receivable, Past Due [Line Items]
Total portfolio loans	596,983	594,668
90+ days past due and still accruing	294	24
Non-Accrual Loans	193	374
Non-Accrual Loans with No Allowance for Credit Losses	0	0
Retail loans \| Retail other \| 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	4,290	2,491
Retail loans \| Retail other \| 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Total portfolio loans	$ 30	$ 79

DERIVATIVE FINANCIAL INSTRUMENTS

3 Months Ended

Mar. 31, 2026

Derivative Instruments and Hedging Activities Disclosure [Abstract]

DERIVATIVE FINANCIAL INSTRUMENTS

NOTE 12. DERIVATIVE FINANCIAL INSTRUMENTS

Busey utilizes interest rate swap agreements as part of its asset liability management strategy to help manage its interest rate risk position. Additionally, Busey enters into derivative financial instruments, including interest rate lock commitments issued to residential loan customers for loans that will be held for sale; forward sales commitments to sell residential mortgage loans to investors; and interest rate swaps and risk participation agreements with customers and other third parties. See “Note 13: Fair Value Measurements” for further discussion of the fair value measurement of such derivatives.

To secure its obligations under derivative contracts, Busey pledged cash and held collateral as follows:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Cash pledged to secure obligations under derivative contracts	$	14,400	$	14,400
Collateral held to secure obligations under derivative contracts	6,750		5,050

Derivative Instruments Designated as Hedges

Busey entered into derivative instruments designated as cash flow hedges. For a derivative instrument that is designated and qualifies as a cash flow hedge, the change in fair value of the derivative instrument is reported as a component of OCI and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. Changes in fair value of components excluded from the assessment of effectiveness are recognized in current earnings.

Interest Rate Swaps Designated as Cash Flow Hedges

Interest rate swaps with notional amounts totaling $700.0 million as of March 31, 2026, and $500.0 million as of December 31, 2025, were designated as cash flow hedges. Busey entered into a $300.0 million receive-fixed, pay-floating interest rate swap to reduce Busey’s asset sensitivity (“Prime Loan Swap”). Duration was added to Busey’s loan portfolio by fixing a portion of floating prime-based loans. Interest rates had risen above their historical lows allowing Busey to lock in a portion of its loan portfolio to reduce asset sensitivity while creating a more stable margin in a volatile rate market. These hedges were determined to be highly effective during the period, and Busey expects its hedges to remain highly effective during the remaining terms of the swaps. Further, Busey entered into forward-starting SOFR-based receive-fixed pay-floating interest rate swaps totaling $400.0 million to reduce Busey’s asset sensitivity (“SOFR Loan Swaps”). These hedges were determined to be highly effective during the period, and Busey expects its hedges to remain highly effective during the remaining terms of the swaps. Changes in fair value were recorded net of tax in OCI.

A summary of the interest-rate swaps designated as cash flow hedges is presented below:


		As of
(dollars in thousands)	Location	March 31, 2026			December 31, 2025
Prime Loan Swap
Notional amount		$	300,000		$	300,000
Weighted average rate: receive-fixed		4.81		%	4.81		%
Weighted average variable Prime pay rates		6.75		%	6.81		%
Weighted average maturity		2.85 years			3.10 years

SOFR Loan Swaps
Notional amount		$	400,000		$	200,000
Weighted average rate: receive-fixed		3.71		%	3.78		%
Weighted average variable 1-month CME Term SOFR pay rates1		3.67		%	3.82		%
Weighted average maturity		5.18 years			3.76 years

Gross aggregate fair value of the swaps
Gross aggregate fair value of swap assets	Other assets	$	1,776		$	3,215
Gross aggregate fair value of swap liabilities	Other liabilities	15,421			14,589

Balances carried in AOCI
Unrealized gains (losses) on cash flow hedges, net of tax	AOCI	$	(9,347)		$	(7,616)

___________________________________________


(dollars in thousands)	As of March 31, 2026

Unrealized gains expected to be reclassified from OCI to interest income	$	481

Changes in interest income recorded on these swap transactions is presented in the following table:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025

Decrease in interest income on swap transactions		$	(1,403)	$	(2,060)

Net gains and losses relating to cash flow derivative instruments that were recorded in OCI on the Consolidated Statements of Income (Unaudited) are presented in the table below:


	Three Months Ended March 31,
(dollars in thousands)		2026		2025
Unrealized gains (losses) on cash flow hedges
Net gains (losses) recognized in OCI, net of tax		$	(2,783)	$	4,641
Losses reclassified from OCI to interest income, net of tax		1,052		1,505

Net change in unrealized gains (losses) on cash flow hedges, net of tax		$	(1,731)	$	6,146

Derivative Instruments Not Designated as Hedges

Interest Rate Swaps Not Designated as Hedges

Busey may offer derivative contracts to its customers in connection with their risk management needs. Busey manages the risk associated with these contracts by entering into equal and offsetting derivative agreements with third-party dealers. These contracts supported variable rate, commercial loan relationships totaling $1.27 billion as of March 31, 2026, and $1.16 billion as of December 31, 2025. These derivatives generally worked together as an economic interest rate hedge, but Busey did not designate them for hedge accounting treatment. Consequently, changes in fair value of the corresponding derivative financial asset or liability were recorded as either a charge or credit to current earnings during the period in which the changes occurred.

Amounts and fair values of derivative assets and derivative liabilities related to customer interest rate swaps recorded on the Consolidated Balance Sheets (Unaudited) are summarized as follows:


		As of March 31, 2026				As of December 31, 2025
(dollars in thousands)	Location	Notional Amount		Fair Value		Notional Amount		Fair Value
Derivative assets not designated as hedging instruments
Interest rate swaps: receive-fixed, pay-floating	Other assets	$	740,117	$	7,355	$	703,286	$	11,542
Interest rate swaps: receive-floating, pay-fixed	Other assets	531,572		17,135		456,973		15,998
Derivative assets not designated as hedging instruments		$	1,271,689	$	24,490	$	1,160,259	$	27,540

Derivative liabilities not designated as hedging instruments
Interest rate swaps: receive-fixed, pay-floating	Other liabilities	$	531,572	$	17,135	$	456,973	$	15,998
Interest rate swaps: receive-floating, pay-fixed	Other liabilities	740,117		7,355		703,286		11,542
Derivative liabilities not designated as hedging instruments		$	1,271,689	$	24,490	$	1,160,259	$	27,540

Changes in fair value of these derivative assets and derivative liabilities were recorded in noninterest expense on the Consolidated Statements of Income (Unaudited) and are summarized as follows:


		Three Months Ended March 31,
(dollars in thousands)	Location		2026		2025
Interest rate swaps
Receive-fixed, pay-floating	Noninterest expense		$	(3,116)	$	3,034
Receive-floating, pay-fixed	Noninterest expense		3,116		(3,034)
Net change in fair value of interest rate swaps			$	—	$	—

Risk Participation Agreements

To manage the credit risk exposure related to customer-facing swaps, Busey entered into risk participation agreements in conjunction with loan participation arrangements with other financial institutions. Under these risk participation agreements, Busey purchased credit risk participation, paying an up-front fee to a counterparty to accept a portion of its credit exposure, and will receive a payment from the counterparty if the swap customer defaults on its obligations. Busey also assumed additional risk participation agreements entered into by CrossFirst, in which CrossFirst purchased credit risk participation, and Busey will receive a payment from the counterparty if the swap customer defaults on its obligations.

In connection with the CrossFirst acquisition, Busey assumed risk participation agreements entered into by CrossFirst, under which CrossFirst sold credit risk participation, receiving an up-front fee from a counterparty in exchange for accepting a portion of the counterparty’s credit exposure. Under these agreements, Busey will be required to make a payment to the counterparty if the swap customer defaults on its obligations.

Notional amounts of the risk participation agreements reflect the participating banks’ pro-rata shares of the derivative instruments, consistent with their shares of the related participated loans. The risk participation agreements mature between May 2026 and October 2033, and are summarized as follows:


	As of
(dollars in thousands)	March 31, 2026		December 31, 2025
Risk participation agreements purchased
Number of risk participation agreements	12		12
Notional amount	$	74,942	$	74,590
Fair value	22		30

Risk participation agreements sold
Number of risk participation agreements	13		13
Notional amount	$	108,242	$	108,743
Fair value	48		65

Foreign Currency Exchange Contracts

Busey entered into foreign currency exchange contracts to support the business requirements of its customers. Foreign currency contracts involve the exchange of one currency for another on a specified date and at a specified rate. These contracts are executed on behalf of Busey's customers and are used by customers to manage fluctuations in foreign exchange rates. Busey generally minimizes its exposure by entering into similar offsetting positions with other financial institutions. Busey is subject to the credit risk that another party will fail to perform. Amounts and fair values of derivative assets and derivative liabilities related to foreign currency contracts recorded on the Consolidated Balance Sheets (Unaudited) are summarized as follows:


		As of March 31, 2026				As of December 31, 2025
(dollars in thousands)	Location	Notional Amount		Fair Value		Notional Amount		Fair Value
Foreign currency exchange forward contracts
Customer contracts	Other assets	$	3,531	$	211	$	—	$	—
Third-party dealer contracts	Other liabilities	629		6		—		—

Mortgage Banking Derivatives

Interest Rate Lock Commitments

Interest rate lock commitments that meet the definition of derivative financial instruments under ASC Topic 815 “Derivatives and Hedging” are carried at their fair values in other assets or other liabilities on the Consolidated Balance Sheets (Unaudited), with changes in the fair values of the corresponding derivative financial assets or liabilities recorded as either a charge or credit to current earnings during the period in which the changes occurred.

Forward Sales Commitments

Busey economically hedges mortgage loans held for sale and interest rate lock commitments issued to its residential loan customers related to loans that will be held for sale by obtaining corresponding forward sales commitments with an investor to sell the loans at an agreed-upon price at the time the interest rate locks are issued to the customers. Forward sales commitments that meet the definition of derivative financial instruments under ASC Topic 815 “Derivatives and Hedging” are carried at their fair values in other assets or other liabilities on the Consolidated Balance Sheets (Unaudited). While such forward sales commitments generally served as an economic hedge to mortgage loans held for sale and interest rate lock commitments, Busey did not designate them for hedge accounting treatment. Changes in fair value of the corresponding derivative financial asset or liability were recorded as either a charge or credit to current earnings during the period in which the changes occurred.

Amounts and fair values of mortgage banking derivatives included on the Consolidated Balance Sheets (Unaudited) are summarized as follows:


		As of March 31, 2026				As of December 31, 2025
(dollars in thousands)	Location	Notional Amount		Fair Value		Notional Amount		Fair Value
Mortgage banking derivative assets
Interest rate lock commitments	Other assets	$	3,139	$	42	$	6,159	$	145
Forward sales commitments	Other assets	6,861		70		1,520		2
Mortgage banking derivative assets		$	10,000	$	112	$	7,679	$	147

Mortgage banking derivative liabilities

Forward sales commitments1	Other liabilities	$	201	$	—	$	9,278	$	26
Mortgage banking derivative liabilities		$	201	$	—	$	9,278	$	26

___________________________________________

1.The fair value of forward sales commitments in a liability position was immaterial, rounding to zero thousand.

Gains and losses relating to these derivative instruments are reported in noninterest income, and are summarized as follows:


		Three Months Ended March 31,
(dollars in thousands)	Location		2026		2025
Net gains (losses) on mortgage banking derivatives
Gains (losses) on interest rate lock commitments	Mortgage revenue		$	44	$	242
Gains (losses) on forward sales commitments	Mortgage revenue		96		(87)


Net gains (losses) on mortgage banking derivatives			$	140	$	155

- Definition

The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts.

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+ Details

BORROWINGS - Schedule of Long-term Borrowings (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2026 USD ($) note	Dec. 31, 2025 USD ($) note
Debt Instrument [Line Items]
Finance lease liabilities	$ 6,178	$ 6,223
Total long-term borrowings	$ 123,467	$ 113,806
Weighted average rate for securities sold under agreements to repurchase	2.40%	2.22%
FHLB borrowings
Debt Instrument [Line Items]
Total long-term borrowings	$ 114,078	$ 102,792
Number of notes \| note	17	15
Weighted average rate for securities sold under agreements to repurchase	2.49%	2.43%
Debt, weighted average maturity period	1 year 8 months 12 days	1 year 11 months 15 days
Secured borrowings
Debt Instrument [Line Items]
Total long-term borrowings	$ 3,211	$ 4,791
Number of notes \| note	6	7
Debt, weighted average maturity period	15 years 4 months 13 days	17 years 3 days

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details