Federal banking regulators — the OCC, FDIC, and Federal Reserve — require banks to classify loans based on the borrower's financial condition and the lender's risk of loss. This regulatory loan classification framework drives a bank's required allowance for loan and lease losses (ALLL, now called the allowance for credit losses or ACL under CECL accounting) and signals to examiners the quality of the bank's credit portfolio.
Loans are classified into five categories. Pass loans are those where the borrower is performing as expected, financial trends are stable or improving, and the lender has little concern about collectibility. Pass is subdivided by some banks into internal grades ranging from minimal risk to acceptable risk, creating a more granular internal rating system. Special Mention designates loans with potential weaknesses that deserve management attention — not yet impaired, but trending in a concerning direction.
Substandard loans are inadequately protected by the current net worth and paying capacity of the borrower or the collateral — there is a distinct possibility of loss if deficiencies are not corrected. Substandard loans should be on the lender's watch list and may require specific reserves. Doubtful loans have all the weaknesses of Substandard loans, with the added element that collection in full is highly questionable — some loss is expected, though the amount cannot yet be determined. Loss loans are considered uncollectible and of such little value that continuation as a bankable asset is not warranted — these loans are charged off.
The classification process is driven by both financial condition and repayment performance. A loan can be classified even if it is current on payments if the borrower's financial condition is sufficiently deteriorated. Conversely, a loan in technical default (covenant violation) may remain Pass if the borrower's fundamentals remain sound and the violation is technical in nature.
Banks must maintain adequate loan loss reserves against classified loans. Under the Current Expected Credit Loss (CECL) model adopted by U.S. banks, reserves are based on lifetime expected credit losses rather than incurred losses — requiring banks to recognize potential credit deterioration earlier in the credit cycle.