If a deposit has not been completed, periods of military service performed after December 31, 1956 (other than periods of military service covered by military leave with pay from a civilian position), are excluded from credit from and after the first day of the month in which the individual (or survivor) becomes entitled, or upon proper application would be entitled, to Social Security benefits under § 202. Military service performed prior to January 1957 is included in the computation of the annuity regardless of whether a deposit is made for service after December 31, 1956.
5 C.F.R. §831.301