((a)) ** Former spouse share of participant’s annuity**
((1)) ** Pro rata share** Unless otherwise expressly provided by a spousal agreement or court order under , a former spouse of a participant, former participant, or retired participant is entitled to an annuity—
((A)) if married to the participant, former participant, or retired participant throughout the creditable service of the participant, equal to 50 percent of the annuity of the participant; or
((B)) if not married to the participant throughout such creditable service, equal to that proportion of 50 percent of such annuity that is the proportion that the number of days of the marriage of the former spouse to the participant during periods of creditable service of such participant under this subchapter bears to the total number of days of such creditable service.
((2)) ** Disqualification upon remarriage before age 55** A former spouse is not qualified for an annuity under this subsection if before the commencement of that annuity the former spouse remarries before becoming 55 years of age.
((3)) ** Commencement of annuity** The annuity of a former spouse under this subsection commences on the day the participant upon whose service the annuity is based becomes entitled to an annuity under this subchapter or on the first day of the month after the divorce or annulment involved becomes final, whichever is later.
((4)) ** Termination of annuity** The annuity of such former spouse and the right thereto terminate on—
((A)) the last day of the month before the month in which the former spouse dies or remarries before 55 years of age; or
((B)) the date on which the annuity of the participant terminates (except in the case of an annuity subject to paragraph (5)(B)).
((5)) ** Treatment of participant’s annuity**
((A)) ** Reduction in participant’s annuity** The annuity payable to any participant shall be reduced by the amount of an annuity under this subsection paid to any former spouse based upon the service of that participant. Such reduction shall be disregarded in calculating—
((i)) the survivor annuity for any spouse, former spouse, or other survivor under this subchapter; and
((ii)) any reduction in the annuity of the participant to provide survivor benefits under subsection (b) or under .
((B)) ** Treatment when annuitant returns to service** If an annuitant whose annuity is reduced under subparagraph (A) is recalled to service under , or reinstated or reappointed, in the case of a recovered disability annuitant, or if any annuitant is reemployed as provided for under sections 2112 and 2113 of this title, the pay of that annuitant shall be reduced by the same amount as the annuity would have been reduced if it had continued. Amounts equal to the reductions under this subparagraph shall be deposited in the Treasury of the United States to the credit of the fund.section 2111 of this title
((6)) ** Disability annuitant** Notwithstanding paragraph (3), in the case of a former spouse of a disability annuitant—
((A)) the annuity of that former spouse shall commence on the date on which the participant would qualify on the basis of the participant’s creditable service for an annuity under this subchapter (other than a disability annuity) or the date on which the disability annuity begins, whichever is later, and
((B)) the amount of the annuity of the former spouse shall be calculated on the basis of the annuity for which the participant would otherwise so qualify.
((7)) ** Election of benefits** A former spouse of a participant, former participant, or retired participant shall not become entitled under this subsection to an annuity payable from the fund unless the former spouse elects to receive it instead of any survivor annuity to which the former spouse may be entitled under this or any other retirement system for Government employees on the basis of a marriage to someone other than the participant.
((8)) ** Limitation in case of multiple former spouse annuities** No spousal agreement or court order under involving a participant may provide for an annuity or a combination of annuities under this subsection that exceeds the annuity of the participant.section 2094(b) of this title
((b)) ** Former spouse survivor annuity**
((1)) ** Pro rata share** Subject to any election under section 2031(b)(1)(B) and (C) of this title and unless otherwise expressly provided by a spousal agreement or court order under , if an annuitant is survived by a former spouse, the former spouse shall be entitled—
((A)) if married to the annuitant throughout the creditable service of the annuitant, to a survivor annuity equal to 55 percent of the unreduced amount of the annuitant’s annuity, as computed under ; and
((B)) if not married to the annuitant throughout such creditable service, to a survivor annuity equal to that proportion of 55 percent of the unreduced amount of such annuity that is the proportion that the number of days of the marriage of the former spouse to the participant during periods of creditable service of such participant under this subchapter bears to the total number of days of such creditable service.
((2)) ** Disqualification upon remarriage before age 55** A former spouse shall not be qualified for an annuity under this subsection if before the commencement of that annuity the former spouse remarries before becoming 55 years of age.
((3)) ** Commencement, termination, and restoration of annuity** An annuity payable from the fund under this subchapter to a surviving former spouse under this subsection shall commence on the day after the annuitant dies and shall terminate on the last day of the month before the former spouse’s death or remarriage before attaining age 55. If such a survivor annuity is terminated because of remarriage, it shall be restored at the same rate commencing on the date such remarriage is dissolved by death, annulment, or divorce if any lump sum paid upon termination of the annuity is returned to the fund.
((4)) ** Survivor annuity amount**
((A)) ** Maximum amount** The maximum survivor annuity or combination of survivor annuities under this subsection (and ) with respect to any participant may not exceed 55 percent of the full amount of the participant’s annuity, as calculated under .section 2031(b)(3) of this titlesection 2031(a) of this title
((B)) ** Limitation on other survivor annuities based on service of same participant** Once a survivor annuity has been provided under this subsection for any former spouse, a survivor annuity for another individual may thereafter be provided under this subsection (or ) with respect to the participant only for that portion (if any) of the maximum available which is not committed for survivor benefits for any former spouse whose prospective right to such annuity has not terminated by reason of death or remarriage.section 2031(b)(3) of this title
((C)) ** Finality of court order upon death of participant** After the death of a participant or retired participant, a court order under may not adjust the amount of the annuity of a former spouse of that participant or retired participant under this section.section 2094(b) of this title
((5)) ** Effect of termination of former spouse entitlement**
((A)) ** Recomputation of participant’s annuity** If a former spouse of a retired participant dies or remarries before attaining age 55, the annuity of the retired participant, if reduced to provide a survivor annuity for that former spouse, shall be recomputed and paid, effective on the first day of the month beginning after such death or remarriage, as if the annuity had not been so reduced, unless an election is in effect under subparagraph (B).
((B)) ** Election of spouse annuity** Subject to paragraph (4)(B), the participant may elect in writing within two years after receipt of notice of the death or remarriage of the former spouse to continue the reduction in order to provide a higher survivor annuity under for any spouse of the participant.section 2031(b)(3) of this title
((c)) ** Optional additional survivor annuities for other former spouse or surviving spouse**
((1)) ** In general** In the case of any participant providing a survivor annuity under subsection (b) for a former spouse—
((A)) such participant may elect, or
((B)) a spousal agreement or court order under may provide for,
((2)) ** Limitation** Neither the total amount of survivor annuity or annuities under this subsection with respect to any participant, nor the survivor annuity or annuities for any one surviving spouse or former spouse of such participant under this section or , may exceed 55 percent of the unreduced amount of the participant’s annuity, as computed under .section 2031 of this titlesection 2031(a) of this title
((3)) ** Contribution for additional annuities**
((A)) ** Provision of additional survivor annuity** In accordance with regulations which the Director shall prescribe, the participant involved may provide for any annuity under this subsection—
((i)) by a reduction in the annuity or an allotment from the basic pay of the participant;
((ii)) by a lump-sum payment or installment payments to the fund; or
((iii)) by any combination thereof.
((B)) ** Actuarial equivalence to benefit** The present value of the total amount to accrue to the fund under subparagraph (A) to provide any annuity under this subsection shall be actuarially equivalent in value to such annuity, as calculated upon such tables of mortality as may from time to time be prescribed for this purpose by the Director.
((C)) ** Effect of former spouse’s death or disqualification** If a former spouse predeceases the participant or remarries before attaining age 55 (or, in the case of a spouse, the spouse predeceases the participant or does not qualify as a former spouse upon dissolution of the marriage)—
((i)) if an annuity reduction or pay allotment under subparagraph (A) is in effect for that spouse or former spouse, the annuity shall be recomputed and paid as if it had not been reduced or the pay allotment terminated, as the case may be; and
((ii)) any amount accruing to the fund under subparagraph (A) shall be refunded, but only to the extent that such amount may have exceeded the actuarial cost of providing benefits under this subsection for the period such benefits were provided, as determined under regulations prescribed by the Director.
((D)) ** Recomputation upon death or remarriage of former spouse** Under regulations prescribed by the Director, an annuity shall be recomputed (or a pay allotment terminated or adjusted), and a refund provided (if appropriate), in a manner comparable to that provided under subparagraph (C), in order to reflect a termination or reduction of future benefits under this subsection for a spouse in the event a former spouse of the participant dies or remarries before attaining age 55 and an increased annuity is provided for that spouse in accordance with this section.
((4)) ** Commencement and termination of additional survivor annuity** An annuity payable under this subsection to a spouse or former spouse shall commence on the day after the participant dies and shall terminate on the last day of the month before the spouse’s or the former spouse’s death or remarriage before attaining age 55.
((5)) ** Nonapplicability of COLA provision** does not apply to an annuity under this subsection, unless authorized under regulations prescribed by the Director.Section 2131 of this title