Military Service Buyback Calculator

A military service buyback (officially called a Military Service Deposit) allows federal civilian employees to purchase credit for their prior active-duty military service. By paying a deposit into the FERS retirement fund, those military years count as FERS service — increasing your eventual pension amount and potentially allowing earlier retirement.

The deposit equals 3% of your total military basic pay earned during the service period. For example, if you earned $120,000 in basic pay over 4 years of active duty, your principal deposit is $3,600. Interest is added if the deposit is not made within 2 years of entering federal civilian service, using OPM's annual interest rate table.

As soon as possible after entering federal service. You have a 2-year interest-free window from your federal hire date. After that, OPM interest begins accruing annually — the rates have ranged from 1.875% to 13% historically. Every year you delay increases your total deposit cost. Contact your HR office or submit SF-3108 to start the process.

Generally, no — not for the same years of service. If you perform the buyback and waive your military retirement, the military service years count toward FERS. If you are already drawing military retirement pay, you can waive it to use the buyback, but this only makes sense in specific circumstances. Reservists with non-regular retirement have different rules. Consult an HR specialist before making this decision.

In most cases, yes — especially if completed promptly while interest is low. The 3% deposit buys a lifetime pension increase equal to 1% of your High-3 salary per military year. For a GS-12 employee with a $90,000 High-3, each military year purchased adds $900/year ($75/month) to a pension paid for life with COLA adjustments. The break-even is typically 5–15 years into retirement, making it financially advantageous for most retirees who live to average life expectancy.