Military Buyback Interest Rates by Year, From 13% to Under 2%

Military Buyback Interest Rates by Year: What the Historical Data Actually Shows

The OPM interest rate on your military service deposit has ranged from 13% in the mid-1980s to below 2% in the early 2020s. That spread is not academic. On a $15,000 deposit left unpaid for a decade, the difference between a 2% and a 4.25% compounding rate is roughly $7,500 in additional cost before you've added a single dollar of retirement income. Understanding military buyback interest rates by year is the prerequisite for any serious analysis of whether the deposit makes financial sense at your income level.

What Are the Military Buyback Interest Rates by Year from 1982 to 2024?

The military service deposit program was established under the Civil Service Retirement System in 1982 and later extended to FERS employees. OPM publishes the annual interest rate applied to unpaid deposit balances, set by the Treasury Department under 5 U.S.C. § 8334(e) and benchmarked to average long-term Treasury yields.

The table below reflects OPM's published rates. Rates peaked in the mid-1980s alongside broader monetary tightening, declined steadily through the 1990s and 2000s, bottomed out during the post-2008 zero-rate era, and have climbed again since 2022.

Source: OPM Interest Rates for Service Credit Deposits and Redeposits; U.S. Department of the Treasury yield curve data.

The 2021 rate of 1.625% represented a generational low. Anyone who completed their deposit in 2021 or 2022 locked in the cheapest buyback in the program's history. The 2024 rate of approximately 4.25% is the highest since 2008, which changes the math materially for anyone still sitting on an unpaid balance.

How OPM Calculates Military Service Deposit Interest

The deposit itself equals 3% of your military base pay for each year of active duty service, per the OPM CSRS and FERS Handbook (Chapter 23). Interest accrues from the midpoint of each period of service, not from your hire date as a federal civilian. That distinction matters more than most people realize.

A veteran who served from 2000 to 2004 and joined federal civilian service in 2006 has interest accruing from approximately 2002 onward. By 2024, that's 22 years of compounding. At the blended historical rate across that period, a $9,000 base deposit (3% of $300,000 in military earnings) could carry an accrued interest balance of $6,000 to $9,000 on top of the principal, depending on the exact rate sequence.

The compounding is annual, not daily. For calculating daily interest rates accurately, the methodology differs from OPM's approach, which applies each year's published rate to the running balance at year-end.

OPM does not charge penalty interest for delay beyond a standard schedule. The interest simply continues to compound at each year's published rate until you pay. That structure means the cost of waiting is directly tied to the current rate environment. At 1.625% in 2021, waiting another year cost almost nothing. At 4.25% in 2024, waiting another year on a $20,000 balance costs $850 in additional interest.

What Is the Current Military Buyback Interest Rate for FERS Employees in 2024?

OPM set the 2024 military service deposit interest rate at approximately 4.25%, consistent with the Federal Reserve's tightening cycle that began in 2022. This is the highest rate since the pre-financial-crisis period and represents a meaningful shift from the sub-2% environment of 2020 and 2021.

For context on where rates may go from here, 10-year interest rate forecasts suggest a gradual normalization rather than a return to zero-rate conditions, which implies deposit costs will remain elevated relative to the 2010s.

The practical implication: if you have an unpaid military service deposit and are more than five years from your federal retirement date, the compounding at 4.25% is now a real cost, not a rounding error. A $25,000 unpaid balance grows to approximately $37,000 over 10 years at this rate. That additional $12,000 comes directly out of the ROI calculation for the buyback.

The rate applies uniformly to both CSRS and FERS employees, though the annuity benefit calculation differs between the two systems. FERS employees generally see a smaller per-year annuity enhancement from the buyback than CSRS employees, which affects the breakeven analysis significantly.

What Is the Breakeven Point for a Military Buyback Deposit Under FERS?

Practitioner literature commonly cites a 5-to-8-year breakeven for a typical FERS military buyback. That figure is accurate for median-income federal employees. It is not accurate for high earners.

The mechanics: under FERS, each year of credited service increases your annuity by 1% of your high-3 average salary (or 1.1% if you retire at 62 or later with 20+ years). A 4-year military buyback on a $150,000 high-3 salary adds approximately $6,000 per year in gross annuity income. If your total deposit cost (principal plus accrued interest) is $15,000, the gross breakeven is 2.5 years. Simple enough.

The problem is taxes.

For a federal employee with $5M or more in assets, FERS pension income is taxed as ordinary income. At a 37% marginal federal rate plus state income tax, that $6,000 annual annuity enhancement nets to roughly $3,600 to $3,900 after federal tax. The after-tax breakeven on a $15,000 deposit is now closer to 4 years, and that still ignores the opportunity cost of the deposit capital.

The delay scenario in the final row is where high-net-worth federal employees most commonly miscalculate. The deposit was affordable and small 10 years ago. Compounded at rising OPM rates, it is now materially larger, and the breakeven has extended by nearly two full years.

For a deeper understanding of understanding rate of return versus interest rate differences, the distinction matters here: the OPM rate is a cost rate on your liability, while the annuity enhancement represents a return on that cost. These are not the same calculation.

Is It Worth Doing a Military Buyback If You Have a High Net Worth?

This is the question the standard federal benefits literature never answers honestly, because it is written for the median federal employee, not for someone with a $5M to $20M net worth.

The conventional answer is "always do the buyback." The reasoning: the annuity is guaranteed, inflation-adjusted (partially, under FERS), and you can't outlive it. All true. But that framing ignores two factors that matter disproportionately at high net worth.

First, you don't need the income. A FERS pension enhancement of $6,000 to $15,000 per year is financially irrelevant to someone with $5M in investable assets generating $150,000 to $250,000 annually. The marginal utility of the additional pension income is low, while the tax drag on it is high.

Second, the deposit capital has a real opportunity cost. If the alternative to a $20,000 deposit is keeping that capital in a diversified portfolio, interest rate investing strategies suggest you can reasonably target 6% to 8% real returns over a long horizon. The FERS annuity enhancement, taxed at 37%, effectively yields 3% to 5% on an after-tax basis. The comparison is not obviously favorable.

That said, three factors can flip the analysis:

1. Longevity. If you have strong family longevity and expect to live to 90 or beyond, the annuity stream becomes very valuable regardless of net worth.
2. Survivor benefit. The buyback enhances the survivor annuity for a spouse, which has estate planning implications that pure ROI calculations miss.
3. Tax bracket timing. Paying the deposit in a lower-income year (a gap year, pre-RMD, pre-Social Security) reduces the after-tax cost of the deposit itself and improves the IRR.

The irreversibility point cuts both ways. Under 5 U.S.C. § 8334 and § 8422, you permanently forfeit military service credit if you separate from federal service without completing the deposit. There is no post-separation remedy. For a federal employee within three years of retirement, this hard deadline often justifies completing the buyback even when the pure ROI is marginal, simply because the option value of the enhanced annuity cannot be recovered later.

How Military Buyback Timing Affects Federal Income Tax Liability for High Earners

The deposit itself is not tax-deductible when paid. You write the check from after-tax dollars. The annuity income it generates is taxable as ordinary income. On the surface, this looks like a straightforward taxable transaction.

The nuance, per IRS Publication 721, is the Simplified Method for calculating the taxable portion of your FERS annuity. A portion of each annuity payment represents a return of your after-tax employee contributions, which reduces the effective tax rate on pension income slightly. This is a small but real adjustment that affects the true after-tax IRR of the buyback.

More significant for high earners is the timing of the deposit payment itself. Consider two scenarios:

Scenario A: You pay the deposit in your final working year at a 37% marginal rate. The deposit is a $20,000 after-tax outflow.

Scenario B: You pay the deposit in a gap year between federal service and Social Security commencement, when your marginal rate drops to 22% or 24%. The same $20,000 deposit costs you less in terms of what you had to earn to fund it, and the after-tax IRR improves accordingly.

This is not a hypothetical. Federal employees who retire early under FERS MRA+10 provisions often have a 2-to-5-year window of lower taxable income before Social Security and RMDs begin. That window is the optimal time to pay a large deposit if you have not already done so. The catch: you must still be a federal employee at the time of payment. Post-separation, the option is gone.

How base rates impact your financial calculations is directly relevant here. The OPM deposit rate is a compounding liability. Every year you delay, the after-tax cost of the deposit rises while your remaining working years to pay it shrink.

Should High-Income Federal Employees Choose Military Buyback or Invest the Deposit Instead?

The honest answer is that this is a closer call than the federal benefits community typically acknowledges, and it depends heavily on your specific numbers.

The framework for the comparison:

Buyback IRR: Take the total deposit cost (principal plus accrued interest), calculate the after-tax annuity enhancement stream over your expected lifespan, and solve for the internal rate of return. For a 65-year-old with a 25-year life expectancy, a $20,000 deposit generating $4,000 per year in after-tax annuity income produces an IRR of approximately 19%. That is exceptional.

For a 55-year-old with a $35,000 deposit (inflated by 10 years of compounding at 4.25%) generating the same $4,000 after-tax per year and a 35-year life expectancy, the IRR drops to approximately 11%. Still strong.

The comparison investment: the Federal Retirement Thrift Investment Board's 2023 TSP Annual Report shows the C Fund (S&P 500 index) has returned approximately 10.4% annualized over the past 10 years. After tax at 37% on long-term capital gains (20% federal plus NIIT), the after-tax return is roughly 7% to 8%. The buyback IRR beats this in most scenarios.

The buyback's after-tax advantage is real, but the table above assumes you complete the deposit before compounding erodes the IRR. The longer you wait, the more the 4.25% OPM rate eats into the return.

For context on how treasury yields versus interest rates interact in this calculation, the OPM deposit rate is derived from Treasury yields, which means in rising-rate environments, the cost of delay and the opportunity cost of the deposit capital both increase simultaneously.

Future Projections for Military Buyback Interest Rates

Predicting OPM deposit rates requires predicting Treasury yields, which requires predicting Federal Reserve policy. The honest answer is that precision is impossible. The directional picture is clearer.

The Federal Reserve's 2024 dot plot and forward guidance suggest a gradual easing cycle beginning in late 2024 or 2025, with the federal funds rate potentially settling in the 3% to 3.5% range by 2026. Long-term Treasury yields, which drive OPM rates, tend to move less dramatically than short-term rates. Interest rate predictions for 2026 from major forecasters generally cluster around a 10-year Treasury yield of 3.5% to 4.5%, implying OPM deposit rates in the 3.5% to 4.5% range through the mid-2020s.

What this means practically: the 1.625% rates of 2021 are not coming back in any near-term scenario. If you are a federal employee with an unpaid military service deposit, the rate environment of the next three to five years is unlikely to be materially more favorable than 2024. Waiting for a rate drop to complete your buyback is a speculative bet against the current consensus.

The more important variable is your own retirement timeline. OPM deposit rates are a secondary consideration compared to the hard deadline of your separation date. The market interest rate formula that drives OPM rates is outside your control. Your retirement date is not.

The Irreversibility Factor: Why This Decision Is Different

Most retirement optimization decisions are reversible or at least adjustable. You can change your TSP allocation, adjust your contribution rate, modify your survivor benefit election before retirement, or rebalance your taxable portfolio. The military service deposit is categorically different.

Under federal statute, if you separate from federal service without completing the deposit, the military service is permanently excluded from your annuity calculation. No appeal, no post-separation payment option, no exception for extenuating circumstances. The OPM CSRS and FERS Handbook (Chapter 23) is explicit on this point.

For a FatFIRE reader who is a senior federal employee approaching retirement, this irreversibility creates an asymmetric risk profile. The downside of completing a buyback that turns out to be marginally suboptimal is small. You paid a few thousand dollars more than the pure IRR would justify. The downside of missing the deadline is permanent: you forfeit the enhanced annuity for the rest of your life and your surviving spouse's life.

This asymmetry argues for completing the deposit earlier than a pure financial optimization would suggest, particularly for employees within five years of their planned separation date. The option value of the enhanced annuity, including the survivor benefit component, is not recoverable with money after the fact.

Practical Steps for Federal Employees Evaluating the Buyback

The decision sequence for a high-net-worth federal employee is more structured than the standard advice suggests.

Step 1: Get your actual deposit amount. Contact your agency's HR office or submit a request to OPM directly. The official deposit statement will show principal owed plus accrued interest through the current date. This is the only number that matters for your analysis. Estimates based on military earnings alone will be materially wrong if you have years of accrued interest.

Step 2: Calculate your annuity enhancement. Under FERS, multiply your years of military service by 1% (or 1.1% if applicable) by your projected high-3 average salary. This is your gross annual annuity increase. Apply your expected marginal tax rate to get the after-tax figure.

Step 3: Run the IRR. Treat the deposit as an upfront investment and the after-tax annuity enhancement as an annual return stream. Solve for IRR over your life expectancy. Compare this to the after-tax return on your next-best alternative for the deposit capital.

Step 4: Assess timing. If you are within three years of retirement, complete the deposit as soon as administratively possible. If you are five or more years out, evaluate whether a lower-income year in the interim offers a tax-timing advantage worth capturing.

Step 5: Factor in the survivor benefit. If you have a spouse who will survive you, the annuity enhancement persists for their lifetime under the FERS survivor benefit election. This materially extends the effective payout horizon and improves the IRR calculation.

The Congressional Research Service's 2022 report on FERS benefits and financing provides the statutory framework for these calculations and is worth reviewing directly if you are modeling this decision in detail.

References

• U.S. Office of Personnel Management (OPM) -- "CSRS and FERS Handbook for Personnel and Payroll Offices, Chapter 23: Military Service"
• U.S. Office of Personnel Management (OPM) -- "Interest Rates for Service Credit Deposits and Redeposits" (annual publication)
• U.S. Department of the Treasury -- "Treasury Yield Curve Rates (Daily Treasury Par Yield Curve Rates)"
• Internal Revenue Service (IRS) -- "Publication 721: Tax Guide to U.S. Civil Service Retirement Benefits" (2023)
• Congressional Research Service (CRS) -- "Federal Employees' Retirement System: Benefits and Financing" (2022)
• Federal Retirement Thrift Investment Board (FRTIB) -- "Thrift Savings Plan Annual Report" (2023)
• U.S. Code, Title 5 -- "5 U.S.C. § 8334 (CSRS) and 5 U.S.C. § 8422 (FERS): Deductions, Contributions, and Deposits"