5 CFR 831.406: Withdrawal of voluntary contributions.

(a) Before receiving additional annuity payments based on the voluntary contributions, a person who has made voluntary contributions may withdraw the balance while still an employee or Member, or after separation.

(b) A person entitled to payment of lump-sum benefits under the CSRS order for precedence set forth in section 8342(c) of title 5, United States Code, is entitled to payment of the balance, if any, on the death of—

(1) An employee or Member;

(2) A separated employee or Member who has not retired;

(3) A retiree, unless a survivor benefit is payable based on an election under § 831.407; or

(4) A person receiving a survivor annuity based on voluntary contributions.