5 CFR § 841.604 - Interest on service credit deposits.
(a) Interest on civilian service credit deposits is computed under § 842.305 of this chapter.
(b) Interest on military service credit deposits is computed under § 842.307 of this chapter.
(c) In the case of a retirement coverage error that was corrected under part 839 (pertaining to errors that lasted for at least 3 years of service after December 31, 1986) in which:
(1) A CSRS service credit deposit was made; and
(2) There is a subsequent retroactive change to FERS, the excess of the amount of the CSRS civilian or military service credit deposit over the FERS civilian or military deposit, together with interest computed under § 842.305 of this chapter, shall be paid to the employee or annuitant. In the case of a deceased employee or annuitant, payment is made to the individual entitled to lump-sum benefits under subpart B of part 843 of this chapter.