5 U.S.C. § 3583

Computations

A computation under this subchapter before reemployment is made in the same manner as if the employee had received basic pay, or basic pay plus additional pay in the case of a Congressional employee, at the rate at which it would have been payable had the employee continued in the position in which he was serving at the time of transfer.

( Pub. L. 89–554 , Sept. 6, 1966 , 80 Stat. 431 .)