How do the CECL methods compare?
| Method | How it works | Suits |
|---|---|---|
| Loss-rate (cumulative) | Lifetime losses on past pools as a share of their original balance, applied to today's pool | Homogeneous loans with stable history |
| Vintage analysis | Loss curves by origination year, projecting each current vintage along its curve | Consumer loans and portfolios with seasonal patterns |
| Roll-rate | Rates at which balances move between delinquency buckets and into default | Credit cards, receivables with delinquency data |
| PD x LGD | Probability of default times loss given default times exposure, over the life | Commercial loans; banks with credit models |
| Discounted cash flow | Expected cash flows discounted at the effective rate, compared with amortized cost | Individually assessed or troubled loans |
| WARM | Average annual loss rate times the remaining life of the pool | Less complex portfolios with limited data |
Whichever method is chosen, and however sophisticated, the inputs matter more than the formula: clean historical data, sensible pools and a well-supported forecast drive the quality of the estimate.
An example: the loss-rate method
A lender reviews five past pools of auto loans. On average, 3.0% of each pool's original balance was lost over its life. Its current pool is $20 million, originated recently, so lifetime losses are expected to follow the same pattern. After adjusting for a forecast of slightly higher unemployment, it uses 3.3%, an allowance of $660,000.
An example: the WARM method
A community bank's commercial real estate loans have an average annual charge-off rate of 0.25% and a weighted-average remaining life of 4 years. The WARM estimate is 0.25% x 4 = 1.0% of the $50 million balance, $500,000, before qualitative adjustments for current conditions and forecasts. The FASB staff has indicated WARM can be acceptable for less complex portfolios, provided the estimate is adjusted for expected changes in balances and conditions.
How should a company choose a CECL method?
- Start from the data available: delinquency history suits roll-rate, origination-year data suits vintage, credit ratings suit PD/LGD.
- Match the method to the portfolio's complexity and materiality; a simple method well documented is better than a complex one poorly supported.
- Different pools can use different methods, for example roll-rate for card balances and PD x LGD for commercial loans.
- Apply qualitative adjustments for factors the method does not capture, documented with evidence.
How long should the forecast period be?
As long as the company can make reasonable and supportable forecasts, which for most companies is one to three years. Beyond that, the estimate reverts to historical loss information. The period is a judgment, documented and applied consistently, and changes only when the company's ability to forecast changes.
How does reversion work?
After the forecast period, a company can revert immediately to its historical loss rates, or gradually, for example straight-line over the following year. Immediate reversion is simpler; gradual reversion avoids a sharp step in the loss curve. The choice should reflect how the company expects conditions to normalize.
What documentation do auditors expect?
A written methodology explaining the pools, the method for each, the data sources, the forecast and reversion approach, and every qualitative adjustment with its evidence. For banks, model validation and back-testing against actual losses are also expected. A simple method that is clearly documented will usually satisfy auditors better than a complex model that is not.
How are forecasts built into each method?
Whatever the method, the estimate must reflect reasonable and supportable forecasts, for example by adjusting loss rates for forecast unemployment or by running PDs under economic scenarios, and revert to historical experience beyond the forecast horizon. See CECL explained, CECL for trade receivables and, for IFRS, IFRS 9 expected credit losses.
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Questions people ask
Which method does CECL require?
None. ASC 326 allows any method that reasonably estimates lifetime expected credit losses.
What is the WARM method?
The weighted-average remaining maturity method: an average annual loss rate multiplied by the pool's remaining life, adjusted for current conditions and forecasts.
What is vintage analysis under CECL?
Projecting losses for each origination year along the loss curve observed for past vintages.
Can different CECL methods be used for different portfolios?
Yes. Each pool can use the method that best suits its characteristics and data.
Sources
Every fee, date and rule on this page was taken from these official and primary sources.
- FASB Accounting Standards Codification: Topic 326, Financial Instruments: Credit Losses
- Financial Accounting Standards Board
Rules and fees change. If you are reading this long after October 4, 2026, confirm the figures with the source before you rely on them.
Related guides
More in ASC 326
This guide is general information. It is not tax or legal advice for your situation.