Frequency of interest crediting.
(C) Frequency of interest crediting. Interest credits under a plan must be provided on an annual or more frequent periodic basis and interest credits for each interest crediting period must be credited as of the end of the period. If a plan provides for the crediting of interest more frequently than annually (for example, daily, monthly or quarterly) based on one of the annual interest rates described in paragraph (d)(3) or (d)(4) of this section, then the plan generally provides an above market rate of return unless each periodic interest credit is determined using an interest crediting rate that is no greater than a pro rata portion of the applicable annual interest crediting rate. However, a plan that credits interest daily based on one of the annual interest rates described in paragraph (d)(3) or (d)(4) of this section is not treated as providing an above market rate of return merely because the plan determines each daily interest credit using a daily interest crediting rate that is 1/360 of the applicable annual interest crediting rate. In addition, interest credits determined, under the terms of a plan, based on one of the annual interest rates described in paragraph (d)(3) or (d)(4) of this section are not treated as creating an effective rate of return that is in excess of a market rate of return merely because an otherwise permissible interest crediting rate for a plan year is compounded more frequently than annually. Thus, for example, if a plan's terms provide for interest to be credited monthly and for the interest crediting rate to be equal to the interest rate on long-term investment grade corporate bonds (as described in paragraph (d)(3) of this section) and the applicable annual rate on these bonds for the plan year is 6 percent, then the accumulated benefit at the beginning of each month could be increased as a result of interest credits by as much as 0.5 percent per month during the plan year without resulting in an interest crediting rate that is in excess of a market rate of return.