(a) If there is no survivor who is entitled to monthly survivor annuity benefits on the death of a former employee, Member, annuitant, or survivor annuitant, the total lump-sum credit to the former employee's or Member's credit in the Retirement Fund is payable, except as provided in section 3716 of title 31, United States Code, on administrative offset for government claims, to the person(s) entitled in the normal order of precedence described in section 8342(c) of title 5, United States Code. If a deceased employee, separated employee, retiree or Member provided in a valid designation of beneficiary that the lump sum proceeds shall be payable to the deceased's estate, or to the Executor, Administrator, or other representative of the deceased's estate, or if the proceeds would otherwise be properly payable to the duly appointed representative of the deceased's estate under the order of precedence specified in 5 U.S.C. 8342(c), payment of the proceeds to the duly appointed representative of the deceased's estate will bar recovery by any other person.

(b) If an annuity is payable, the former employee, Member or the person entitled in the order of precedence described in section 8342(c) of title 5, United States Code, may be paid, except as provided in section 3716 of title 31, United States Code, administrative offset for government claims, lump-sum payment of—

(1) Retirement deductions withheld from the employee's or Member's pay after he or she became eligible for the maximum annuity, if the employee or Member does not elect to treat those deductions as voluntary contributions toward the purchase of an additional annuity; and

(2) Retirement deductions withheld from the employee's or Member's pay during his or her final period of service if the employee or Member was not subject to the retirement system for at least one of the last 2 years before final separation from service and if the service covered by the deductions is not used for title to annuity; and

(3) Except as provided in paragraph (d) of this section, partial redeposits of refunds previously paid; and

(4) Partial deposits for civilian service performed on and after October 1, 1982; and

(5) Partial deposits for post-1956 military service; and

(6) Annuity accrued and unpaid.

(c) A former employee, Member, or survivor who is eligible for an annuity may not be paid a lump-sum payment of—

(1) Partial or completed deposits for nondeduction civilian service performed before October 1, 1982, unless the service covered by the deposit is not creditable under the retirement system; or

(2) Completed deposits for nondeduction civilian service performed on and after October 1, 1982, unless the service covered by the deposit is not creditable under the retirement system; or

(3) Completed deposits for post-1956 military services, unless the service covered by the deposit is not creditable under the retirement system.

(d) A former employee or Member who is eligible for a nondisability annuity may not be paid a lump-sum payment of a partial redeposit for refunded deductions relating to a period of service that ended before October 1, 1990.