| AAA | Determined to have almost no risk of loss due to credit-related events. Assigned only to the very highest quality obligors and obligations able to survive extremely challenging economic events. |
| AA | Determined to have minimal risk of loss due to credit-related events. Such obligors and obligations are deemed very high quality. |
| A | Determined to be of high quality with a small risk of loss due to credit-related events. Issuers and obligations in this category are expected to weather difficult times with low credit losses. |
| BBB | Determined to be of medium quality with some risk of loss due to credit-related events. Such issuers and obligations may experience credit losses during stress environments. |
| BB | Determined to be of low quality with moderate risk of loss due to credit-related events. Such issuers and obligations have fundamental weaknesses that create moderate credit risk. |
| B | Determined to be of very low quality with high risk of loss due to credit-related events. These issuers and obligations contain many fundamental shortcomings that create significant credit risk. |
| CCC | Determined to be at substantial risk of loss due to credit-related events, near default or in default with high recovery expectations. |
| CC | Determined to be near default or in default with average recovery expectations. |
| C | Determined to be near default or in default with low recovery expectations. |
| D | Default. |
