Military Time
Buy Back.
If you served on active duty before joining federal civilian service, you may be able to buy back that military time and have it count toward your retirement annuity. The rules — and the dollar value — differ significantly between CSRS and FERS.
How military
buy back works.
Federal employees can make a military deposit to have their active duty service counted toward their civilian retirement annuity. The deposit amount is a percentage of your military base pay — far less than the annuity increase it typically generates.
Approximately 33% of all federal employees are veterans. Making a military deposit adds those service years to your civilian retirement calculation — increasing your lifetime annuity for a one-time payment that is often recovered within the first few years of retirement.
When you make a military deposit, your military service time is added to your federal service when calculating your retirement annuity. However, it does not count toward the minimum service requirement for retirement eligibility. You must still meet the civilian service minimums to qualify for a retirement annuity.
Making a military deposit has no effect on your military benefits — base access, commissary, VA disability, or medical benefits are unaffected. It only affects active duty retired military pay.
You cannot receive two separate retirements (military and civilian) for the exact same period of service. Reserve or National Guard members under Title 32, however, can collect both a federal civil service retirement and a reserve or National Guard retirement.
Eligibility example
If you hire into federal service at age 58, you must work at least 5 years to age 63 to be eligible for a retirement annuity — military buy back time does not count toward that 5-year minimum. However, if you purchased back 4 years of military service, you would retire at 63 with 9 years toward your annuity calculation instead of 5 — nearly doubling your monthly benefit.
CSRS & FERS
rules compared.
The rules differ significantly between CSRS and FERS — and for CSRS employees, the consequences of not buying back depend on whether you'll be eligible for Social Security at age 62. Know which rules apply to you before making any decisions.
CSRS Rules
Civil Service Retirement System
FERS Rules
Federal Employees Retirement System
FERS deposit amount example
At 3% of military base pay, the deposit is typically modest — especially for service during periods of lower military pay. The annuity gain, however, compounds over a full retirement lifetime. For a FERS employee with 4 years of military service and a projected high-3 of $80,000:
Annuity increase: 4 years × 1% × $80,000 = $3,200/year — for a one-time deposit of a few hundred to a few thousand dollars.
Calculate your deposit & annuity gain.
Enter your military service years and pay history to estimate your deposit cost, the interest owed, and the lifetime annuity increase from buying back your military time.
Federal Retirement
Military Buy Back Calculator
Estimate military service deposit and retirement impact with the same clean planning flow used across our newer calculators.
Complete the quick lead form to unlock your personalized military buy back estimate.
Unlock the Military Buy Back Calculator
Enter your information to unlock the calculator instantly on this page.
Step 2: Build your estimate
Switch between Basic and Advanced modes to estimate military service deposit and retirement impact.
Should you buy back
if you're already retired military?
If you receive a military retirement annuity, buying back your military time requires you to waive that military retired pay in exchange for including those years in your civilian retirement calculation. This is not always the right call — run the numbers first.
| Scenario | Decision | Why |
|---|---|---|
| FERS annuity increase > military retired pay | Buy back | You come out ahead by combining service into the civilian annuity and waiving military pay |
| Military retired pay > FERS annuity increase | Do not buy back | Keep your military retirement — waiving it would reduce total income |
| FERS and military pay are close | Model both | Factor in COLA differences, survivor benefits, and health coverage before deciding |
FERS calculation for retired military
To estimate the FERS gain: multiply your years of military service × 1% (or 1.1% if retiring at 62 with 20+ years) × your projected high-3 average salary.
Example: 20 years military service × 1% × $80,000 projected high-3 = $16,000/year annuity increase. If your military retired pay is less than $16,000/year — buying back likely makes sense. If it's more, keep it separate.
Step-by-step: how to make the military deposit
Contact your agency Human Resources department
Before anything else, contact your agency HR office to initiate the military deposit process. They will provide the correct form and guidance on how to submit it.
Complete the appropriate form
FERS employees: Complete SF-3108 — Application to Make Service Credit Payment / FERS.
CSRS employees: Complete SF-2803 — Application to Make Deposit or Redeposit / CSRS.
You will also need Form RI 20-97 (Estimated Earnings During Military Service) to establish your military base pay for the deposit calculation.
Choose your payment method
You can make payments through payroll deduction (spread across pay periods) or pay a lump sum directly. Payroll deduction is the most common approach and avoids large out-of-pocket payments.
Verify payment is recorded before you retire
Confirm that your Leave and Earnings Statement (LES) reflects the buyback deductions or shows "balance owed $0." Check that the "DG-66" form — Record of Military Buy Back Paid in Full — is in your Official Personnel Folder (OPF) or electronic OPF (eOPF). Do not assume this happens automatically.
Payment confirmation issues
Payment confirmation problems are a known issue. Military deposit payments are made directly to your payroll office — bypassing HR — so confirmation documentation often doesn't automatically end up in your OPF.
If you can't find confirmation of your buy back
If you believe you made the deposit but cannot find the DG-66 confirmation form, start with your payroll office (DFAS, NFC, or your agency's payroll processor) — not HR. They maintain the deposit payment records.
Review your biweekly LES statements for the deduction entries. If you paid by lump sum, check for a cancelled check or agency receipt. If confirmation says "deposit complete" or "balance owed $0" on your LES, that is often sufficient documentation.
When you retire, OPM receives paperwork from HR → payroll → OPM. Most deposits are verified correctly at the payroll stage even if the document is not in the OPF. But do not rely on this — obtain written confirmation before your retirement date.
National Guard service
National Guard service is rarely creditable toward a civilian retirement. It qualifies only under specific federal activation conditions — not general state-level Guard service.
National Guard service is creditable only if performed:
Under a call by the President of the United States; or pursuant to orders under authority of Section 233(d) of the Armed Forces Reserve Act of 1952; or pursuant to orders under authority of a provision of Title 10 of the U.S. Code.
National Guard service, even if performed for a federally recognized unit, is not creditable unless it meets one of the above conditions. Reserve members under Title 32 can, however, collect both a federal civil service retirement and a reserve or Guard retirement simultaneously.
Forms &
further reading.
Official OPM forms, DFAS guidance, handbook chapters, and tools for calculating and completing your military deposit.