Allows a federal agency head to waive the application of civil service retirement system and federal employee retirement system provisions restricting annuities and pay upon reemployment with respect to an annuitant employed on a temporary basis, but prohibits waiving such provisions with respect to an annuitant for more than: (1) 520 hours of service performed during the six months following the individual's annuity commencing date; (2) 1040 hours of service performed during any 12-month period; or (3) 6240 hours of service performed during the individual's lifetime.