At each reporting date, an entity shall record an allowance for credit losses that reflects the amount of the impairment related to credit losses, limited by the amount that fair value is less than the amortized cost basis. Changes in the allowance shall be recorded in the period of the change as credit loss expense (or reversal of credit loss expense).
Impairment shall be assessed at the individual security level (referred to as an investment). The impairment assessment of the individual securities or individual beneficial interest in a closed portfolio hedged using the portfolio layer method shall not consider the basis adjustment related to an existing portfolio layer method hedge. Individual security level means the level and method of aggregation used by the reporting entity to measure realized and unrealized gains and losses on its debt securities. (For example, debt securities bearing the same Committee on Uniform Security Identification Procedures [CUSIP] number that were purchased in separate trade lots may be aggregated by a reporting entity on an average cost basis if that corresponds to the basis used to measure realized and unrealized gains and losses for the debt securities.) Providing a general allowance for an unidentified impairment in a portfolio of debt securities is not appropriate.
An entity shall not combine separate contracts (a debt security and a guarantee or other credit enhancement) for purposes of determining whether a debt security is impaired or can contractually be prepaid or otherwise settled in such a way that the entity would not recover substantially all of its cost.
As an accounting policy election for each major security type of debt securities classified as available-for-sale securities, an entity may adjust the effective interest rate used to discount expected cash flows to consider the timing (and changes in the timing) of expected cash flows resulting from expected prepayments.
The estimates of expected future cash flows shall be the entity's best estimate based on past events, current conditions, and on reasonable and supportable forecasts. Available evidence shall be considered in developing the estimate of expected future cash flows. The weight given to the information used in the assessment shall be commensurate with the extent to which the evidence can be verified objectively. If an entity estimates a range for either the amount or timing of possible cash flows, the likelihood of the possible outcomes shall be considered in determining the best estimate of expected future cash flows.
Available information would include existing environmental factors, for example, existing industry, geographical, economic, and political factors that are relevant to the collectibility of that debt security.