(a) Subject to the adjustment described in paragraph (c) of this section, a phased retiree's composite retirement annuity at final retirement equals the sum obtained by adding—

(1) The amount computed under § 831.1741(a) without adjustment under § 831.1741(b) and (c), increased by cost-of-living adjustments under § 831.1743(c); and

(2) The “fully retired phased component” computed under paragraph (b) of this section.

(b)(1) Subject to the requirements described in paragraphs (b)(2) and (b)(3) of this section, a “fully retired phased component” equals the product obtained by multiplying—

(i) The working percentage; by

(ii) The amount of an annuity computed under 5 U.S.C. 8339 that would have been payable at the time of full retirement if the individual had not elected phased retirement status and as if the individual was employed on a full-time basis in the position occupied during the phased retirement period and before any reduction for survivor annuity.

(2) In applying paragraph (b)(1)(ii) of this section, the individual must be deemed to have a full-time schedule during the period of phased retirement. The deemed full-time schedule will consist of five 8-hour workdays each workweek, resulting in a 40-hour workweek. In determining the individual's deemed rate of basic pay during phased retirement, only basic pay for hours within the deemed full-time schedule will be considered, consistent with the definition of “full-time” in § 831.1702. Any premium pay creditable as basic pay for retirement purposes for overtime work or hours outside the full-time schedule that an employee was receiving before phased retirement, such as standby duty pay under 5 U.S.C. 5545(c)(1) or customs officer overtime pay under 19 U.S.C. 267(a), may not be considered in determining a phased retiree's deemed rate of basic pay during phased retirement.

(3) In computing the annuity amount under paragraph (b)(1) of this section—

(i) The amount of unused sick leave equals the result of dividing the days of unused sick leave to the individual's credit at separation for full retirement by the working percentage; and

(ii) The reduction for any unpaid deposit for non-deduction service performed before October 1, 1982, is based on the amount of unpaid deposit, with interest computed to the commencing date of the composite annuity.

(c) The composite retirement annuity computed under paragraph (a) of this section is adjusted by applying any reduction for any survivor annuity benefit.

(d) The monthly installment derived from a composite retirement annuity computed under paragraph (a) of this section and adjusted under paragraph (c) is adjusted by any—

(1) Actuarial reduction applied to the phased retirement annuity under § 831.1741(b), increased by cost-of-living adjustments under § 831.1743(d); and

(2) Offset under § 831.1005 (i.e., the offset based on all service, including service during the phased retirement period, performed by the individual that was subject to mandatory Social Security coverage).