5 C.F.R. § 843.201

This subpart explains the requirements under FERS—

(a) For payment of employee contributions to the Civil Service Retirement Fund—

(1) As a refund of contribution, to separated employees; or

(2) As a death benefit, to survivors of employees, separated employees, and retirees; and

(b) For payment of any accrued, but unpaid, annuity to survivors of retirees.