Part time credit toward retirement annuity

Under CSRS/CSRS-Offset and FERS, the high-three average salary used for part-time work is the salary that would have been paid if the employee had worked full-time, and the basic benefit formula is the same. However, the calculation is adjusted by a factor determined by dividing the actual hours worked by the full-time hours available over the creditable federal service time.

PL 111-84 of 2009 required OPM to calculate annuities under CSRS based on the highest three average pay for the position he or she occupied regardless of when. Under the prior policy, years of part-time service might not have been used for determining the high-three average salary, even though the hourly salary in those years might have been among the highest three.