5 CFR 831.662: Deposits required to change an election after final adjudication.

The amount of the deposit required under § 831.622 or § 831.685 equals the sum of the monthly differences between the annuity paid to the retiree and the annuity that would have been paid if the additional annuity reduction elected under § 831.622 or § 831.685 had been in effect since the time of retirement, plus 24.5 percent of the increase in the designated base (computed as of the time of retirement) on which the survivor annuity is calculated.