FERS Retirement Calculator

It is a deposit of 3% of the military basic pay you earned on active duty (3.25% for pay earned in 1999, 3.4% for 2000). Once paid, those years become creditable FERS service and add 1% - or 1.1% if you retire at 62+ with 20+ years - of your high-3 to your annuity for every bought-back year, for life. Buying back about four years for a few thousand dollars can permanently raise the pension by roughly 4% of high-3 a year, so it usually pays for itself within a handful of years of retirement.

There is a 2-year interest-free window measured from the date you were first employed subject to FERS. Pay in full before that ends and no interest accrues; because interest is first charged one year after the grace period (on the Interest Accrual Date), paying before that first date gives an effective window of about three years. After that a variable Treasury rate compounds annually on the unpaid balance. The deposit must be completed before you separate from federal service or the military years cannot be credited.

They count toward the 20-year and 30-year service thresholds and toward the years-of-service factor in the annuity formula. They do NOT count toward the mandatory 5-year minimum of civilian service required for any FERS annuity, and they are excluded from the FERS annuity supplement /40 proration, which uses civilian FERS years only.