(a) General. In addition to the cost-of-living increase explained in § 404.275 for a given year, we will further increase the amounts in § 404.271 if—

(1) The OASDI fund ratio is more than 32.0 percent in the given year in which a cost-of-living increase is due; and

(2) In any prior year, the cost-of-living increase was based on the AWI as the lower of the CPI and AWI.

(b) Measuring period for the additional increase—(1) To compute the additional increase for all individuals and for maximum benefits payable to a family, we begin with the year in which the insured individual became eligible for old-age or disability benefits to which he or she is currently entitled, or died before becoming eligible.

(2) Ending. The end of the measuring period is the year before the first year in which a cost-of-living increase is due based on the CPI and in which the OASDI fund ratio is more than 32.0 percent.

(c) Compounded percentage benefit increase. To compute the additional cost-of-living increase, we must first compute the compounded percentage benefit increase (CPBI) for both the cost-of-living increases that were actually paid during the measuring period and for the increases that would have been paid if the CPI had been the basis for all the increases.

(d) Computing the CPBI. The computation of the CPBI is as follows—

(1) Obtain the sum of (i) 1.000 and (ii) the actual cost-of-living increase percentage (expressed as a decimal) for each year in the measuring period;

(2) Multiply the resulting amount for the first year by that for the second year, then multiply that product by the amount for the third year, and continue until the last amount has been multiplied by the product of the preceding amounts;

(3) Subtract 1 from the last product;

(4) Multiply the remaining product by 100. The result is what we call the actual CPBI.

(5) Substitute the cost-of-living increase percentage(s) that would have been used if the increase(s) had been based on the CPI (for some years, this will be the percentage that was used), and do the same computations as in paragraphs (d) (1) through (4) of this section. The result is what we call the assumed CPBI.

(e) Computing the additional cost-of-living increase. To compute the percentage increase, we—

(1) Subtract the actual CPBI from the assumed CPBI;

(2) Add 100 to the actual CPBI;

(3) Divide the answer from paragraph (e)(1) of this section by the answer from paragraph (e)(2) of this section, multiply the quotient by 100, and round to the nearest 0.1. The result is the additional increase percentage, which we apply to the appropriate amount described in § 404.271 after that amount has been increased under § 404.275 for a given year. If that increased amount is not a multiple of $0.10, we will decrease it to the next lower multiple of $0.10.

(f) Restrictions on paying an additional cost-of-living increase. We will pay the additional increase to the extent necessary to bring the benefits up to the level they would have been if they had been increased based on the CPI. However, we will pay the additional increase only to the extent payment will not cause the OASDI fund ratio to drop below 32.0 percent for the year after the year in which the increase is effective.