Military Service Buyback Tax Treatment: Are Deposits Tax-Deductible?

The Tax Question Nobody Asks Until It's Too Late

Military buyback — making a deposit to OPM to credit your active-duty time toward your FERS or CSRS annuity — is one of the best financial moves available to federal employees with prior military service. The deposit increases your creditable service years, which directly increases your annuity calculation. But the tax treatment of that deposit catches many retirees off guard, both during the payment phase and decades later when they start collecting the pension.

Here's the core issue: you're paying into the federal retirement system using after-tax dollars, and those payments create a "cost basis" that changes how much of your pension is taxable in retirement. Get the tax treatment wrong and you'll either overpay taxes on your annuity or miss out on deductions you were entitled to.

Are Military Buyback Deposits Tax-Deductible?

No. Military service deposits paid to OPM are not deductible on your federal income tax return. You cannot claim them as an adjustment to income, an itemized deduction, or a credit. The IRS treats military buyback deposits the same way it treats mandatory FERS employee contributions — as after-tax payments into a qualified retirement plan.

This is true regardless of whether you pay the deposit in a lump sum or through payroll deductions over several years. The deposit amount and any accrued interest you pay are all after-tax dollars from the IRS's perspective.

Where this gets confusing: some federal employees assume that because the buyback is a "retirement contribution," it should be deductible like a traditional IRA contribution. It's not. The mandatory employee contributions that come out of your paycheck for FERS (currently 0.8% to 4.4% of basic pay depending on your FERS category) aren't deductible either — they show up on your W-2 as part of your gross wages but are treated as after-tax contributions to the retirement fund.

How Buyback Deposits Affect Your Annuity Taxation

Here's where the tax benefit actually shows up: your military buyback deposit becomes part of your total after-tax contributions to the federal retirement fund. When you retire and start collecting your annuity, a portion of each monthly payment is considered a tax-free return of those contributions.

The IRS requires retirees with annuity starting dates after November 18, 1996, to use the Simplified Method (IRS Publication 721) to calculate the tax-free portion. The formula divides your total after-tax contributions — which now includes your military deposit — by an IRS expected-payment factor based on your age at retirement:

Example: You retire at 60 with $85,000 in total after-tax contributions, of which $22,000 came from your military buyback deposit (base deposit plus interest). Using the single-life factor of 310:

$85,000 ÷ 310 = $274.19 per month tax-free

Without the buyback deposit, your total after-tax contributions would have been $63,000, yielding:

$63,000 ÷ 310 = $203.23 per month tax-free

That $70.96 monthly difference — roughly $851 per year — adds up. Over the 310-month recovery period, you'd recover the full $22,000 tax-free. The buyback deposit doesn't create a new tax deduction; it shifts when you get the tax benefit — from the deposit years to the retirement years, spread across decades of annuity payments.

Interest on the Buyback Deposit

If you don't complete your military service deposit during the applicable interest-free period, OPM adds interest to the outstanding balance. For FERS, interest generally begins two years after the effective date of your election to join FERS; for CSRS, it generally begins two years after you first become subject to CSRS. The deposit can generally be completed within three years of that date without interest. Rates are set annually by the Treasury Department and vary by interest-accrual date.

The interest you pay is also not tax-deductible. However, the interest payment does count toward your total after-tax contributions, which means it increases the tax-free portion of your future annuity through the Simplified Method. So while you can't deduct the interest in the year you pay it, you recover it tax-free over the course of your retirement.

This creates a secondary consideration for timing: paying the deposit early (before interest accrues) means you pay less total but have a slightly smaller cost basis. Paying later means you pay more (deposit plus interest), but your tax-free monthly recovery is also higher. In most cases, paying early is still the better financial move because the interest rate exceeds the implicit "return" of spreading the recovery across retirement years.

Tracking Your Contributions for Tax Purposes

When OPM finalizes your annuity after retirement, they'll issue a statement showing your total after-tax contributions — including your military buyback deposit. This figure appears in Box 9b of your annual Form CSA-1099-R and drives your Simplified Method calculation.

The critical paperwork to keep:

• Form RI 92-19 / RI 83-21: Documents used to calculate military deposits and document service buy-back transitions before retirement submission; keep the completed records showing the deposit amount and completion date
• DD-214: Verifying your military service dates (which determine the base pay period for calculating the deposit)
• Military Deposit Paid-in-Full letter: Confirmation from your agency's payroll office that the deposit was completed
• Pay stubs or receipts showing each installment if you paid through payroll deduction

If your buyback deposit doesn't appear correctly in OPM's records — if the total after-tax contributions on your CSA-1099-R are too low — you'll be overpaying taxes on your annuity every month. This is worth auditing during the first year of retirement: compare the total contributions figure on your 1099-R against your own records (career FERS deductions from pay stubs plus the military deposit amount). If there's a discrepancy, contact OPM at 1-888-767-6738 to request a correction before filing that year's tax return.

If You Waived Military Retired Pay

Federal employees who are also military retirees face an additional layer. To receive civilian retirement credit for military service performed after 1956, you generally must waive your military retired pay unless it falls within a statutory exception, such as qualifying service-connected disability retired pay or reserve-component retired pay. The waived military retired pay stops being taxable to you — but only after the waiver takes effect.

In the year of transition, you may receive a partial year of military retired pay (taxable, reported on a 1099-R from DFAS) and a partial year of the increased civilian annuity (with the larger tax-free recovery). Make sure your tax professional accounts for both income streams and the mid-year transition in the first filing season after the waiver.

Our Federal Retirement Tax toolkit includes a First-Year Filing Prep Worksheet designed for exactly this scenario — reconciling multiple 1099-Rs, calculating the correct Simplified Method exclusion, and identifying the forms you'll need to bring to your CPA.