other retirement systemmeans a program created by Federal or District of Columbia statute or regulation and administered by an agency of the Federal Government or District of Columbia that provides retirement and/or death benefits to Federal or District of Columbia employees whose employment would otherwise be subject to the provisions of CSRS or FERS, or that credits service in the computation of benefits that would otherwise be credited in the computation of a CSRS or FERS benefit, or that provides a death benefit when a death benefit is payable from CSRS or FERS.