D.C. Code § 5-1303
Service in Armed Forces — Rank or grade preserved; restriction on compensation.
No officer or member of the Metropolitan Police force or of the Fire Department of the District of Columbia shall, by reason of the enactment of § 5-1302 , be:
(1) Reduced in rank or grade; or
(2) Entitled to any compensation for any period prior to July 1, 1947.