(1) In computing the annuity under subchapter III of chapter 83, or subchapter II of chapter 84, of title
5 of an individual who retires under such subchapter (other than under section 8337 or 8451 of such title) after December 31, 1981, and who served at any time on a less-than-full-time basis in a position in the Administration to which such individual was appointed under subchapter I
(A) for the purpose of determining such individuals average pay, as defined by section
8331 (4) or
8401 (3) of title
5, whichever is applicable, the annual rate of basic pay for full-time service shall be deemed to be such individuals rate of basic pay; and
(B) the amount of such individuals annuity as computed under section
8339 or
8415 of title
5 (before application of any reduction required by subsection (i) of section 8339) shall be multiplied by the fraction equal to the ratio that that individuals total full-time equivalent service bears to that individuals creditable service as determined under section
8332 or
8411 of title
5, whichever is applicable.
(2) For the purposes of paragraph (1)(B), an individuals full-time equivalent service is the individuals creditable service as determined under section
8332 or
8411 of title
5, whichever is applicable, except that any period of service of such individual served on a less-than-full-time basis shall be prorated based on the fraction such service bears to full-time service. For the purposes of the preceding sentence, full-time service shall be considered to be 80 hours of service per biweekly pay period.
(3) A survivor annuity computed under section
8341, or subchapter IV of chapter 84, of title
5 based on the service of an individual described in paragraph (1) shall be computed based upon such individuals annuity as determined in accordance with such paragraph.
