5 CFR 831.2209 - Redetermined annuity after reemployment.
(a) For purposes of this section, “lump-sum credit” does not include -
(1) The amount by which the lump-sum credit attributable to service performed before the annuitant's first retirement was reduced by annuity payments that were not reimbursed by the employing agency under section 8344(a) of title 5, United States Code, or
(2) Any part of the lump-sum credit attributable to service performed before the annuitant's first retirement that has already been paid to the annuitant pursuant to an election or an alternative form of annuity.
(c) To compute the beginning rate of the redetermined annuity payable to an annuitant who elects an alternative form of annuity, OPM will first compute the monthly rate payable under subchapter III of chapter 83 of title 5, United States Code, including all reductions provided under the subchapter other than those in section 8343a. That monthly rate is then reduced by the sum of -
(d) The beginning rate of a redetermined annuity payable to an annuitant who does not elect, or is not eligible to elect, an alternative form of annuity will be reduced in accordance with paragraph (c)(1) of this section.