(a) Eligible participants; election of benefits
Any participant or former participant in the Foreign Service Retirement and Disability System who on February 15, 1981, has a former spouse may, by a spousal agreement, elect to receive a reduced annuity and provide a survivor annuity for such former spouse under section 4054(b) of this title.

(b) Time of election

(1) If the participant or former participant has not retired under such system on or before February 15, 1981, an election under this section may be made at any time before retirement.

(2) If the participant or former participant has retired under such system on or before February 15, 1981, an election under this section may be made within such period after February 15, 1981, as the Secretary of State may prescribe.

(3) For purposes of applying subchapter VIII of this chapter, any such election shall be treated the same as if it were a spousal agreement under section 4060(b)(1) of this title.

(c) Portion of annuity as basis for benefits
An election under this section may provide for a survivor benefit based on all or any portion of that part of the annuity of the participant which is not designated or committed as a base for survivor benefits for a spouse or any other former spouse of the participant. The participant and his or her spouse may make an election under section 4046(b)(1)(B) of this title prior to the time of retirement for the purpose of allowing an election to be made under this section.

(d) Amount of reduction; effective date
The amount of the reduction in the participant's annuity shall be determined in accordance with section 4046(b)(2) of this title. Such reduction shall be effective as of—

(1) the commencing date of the participant's annuity, in the case of an election under subsection (b)(1), or

(2) February 15, 1981, in the case of an election under subsection (b)(2).

(e) Definitions
For purposes of this section, the terms "former spouse", "participant", and "spousal agreement" have the meanings given such terms in sections 4043 and 4044 of this title.