CECL model validation can support continuous model improvement, resulting in more efficient capital allocation by community banks. The Current Expected Credit Loss (CECL) accounting standard (ASC 326) stipulates that institutions estimate and reserve for credit losses over the life of financial assets using historical experience, current conditions, and reasonable and supportable forecasts. In this quick note we assess the impact of CECL adoption on loss reserve levels at U.S. small community banks and large commercial banks.
CECL typically increases upfront allowance levels at adoption and can raise volatility in reserves due to forward-looking forecasts. It requires stronger data, documentation, and model governance, often prompting upgrades to loan-level data systems, stress-testing practices, and capital planning. Figure 1 shows the ratio of loan and lease loss allowances to the loan and lease totals. The vertical dashed line represents the final CECL adoption date, January 1, 2023. The loan allowance as a fraction of the total of leases and loans (the Ratio in the figure) increased post final CECL adoption for both small community banks and large commercial banks. The small-bank ratio appears to plateau just below
Figure 1- Ratio of loss allowances to total lease and loans. The declining ratio for large banks (green curve) suggests increasingly sophisticated loss modeling facilitates more efficient capital allocation. Author’s calculation using Board of Governors of the Federal Reserve System (US) data. 1
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1 The timeseries data are sourced from Board of Governors of the Federal Reserve System (US), retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series, February 11, 2026. The Large-Bank ratio is calculated as ALLLCBM027NBOG / LLBLCBM027NBOG, and the Small-Bank ratio is calculated as ALLSCBM027NBOG / LLBSCBM027NBOG.
1.4%, whereas the large-bank ratio is trending downward after peaking at approximately 2%. We believe this downward trend is partly due to the higher CECL-modeling sophistication of larger banks with their higher capacity to continuously improve their loss reserve modeling. Model validation of these large-bank CECL models supports this continuous improvement. The downward trend also indicates the large banks are increasing their capital efficiency by liberating reserves to other uses, e.g., loan origination.
The April 2023 Interagency Policy Statement on Allowances for Credit Losses states that banks must validate CECL models to ensure they are conceptually sound, consistently implemented, and produce reasonable loss estimates given the institution’s size, complexity, and risk profile. Martingale Solution Group is your strategic partner for regulatory-compliant value-adding CECL model validations. A great validation can lead to continuous CECL modeling improvements to achieve higher capital efficiency. Contact Martingale Solution Group today for a model validation consultation.
