Military retirement is one of the few remaining true defined benefit pensions that still accrues for most participants. But the system changed fundamentally with the Blended Retirement System (BRS) in 2018, and if you entered service after January 1, 2018 or opted into BRS during the 2018 to 2019 election window, your retirement works differently than it did for previous generations of servicemembers.
The Legacy Retirement System (High-3)
Under the legacy system, servicemembers who serve 20 or more years receive a monthly retirement payment equal to: 2.5% times years of service times the average of the highest 36 months of base pay.
A servicemember retiring at exactly 20 years receives 50% of their high-3 average base pay. At 30 years, 75%. The retirement begins immediately upon separation, no waiting until age 60 or 65, and includes annual COLA tied to the Consumer Price Index, making it one of the most inflation-protected defined benefit pensions available anywhere in the economy.
The major limitation: it requires 20 years. A servicemember who separates at 18 years receives nothing under the legacy system. No partial pension, no vested benefit. This cliff vesting structure is unique among major pension programs.
The Blended Retirement System (BRS)
BRS applies to servicemembers who entered service on or after January 1, 2018, and those who opted in from 2018 to 2019. Under BRS, the retirement multiplier is reduced to 2.0% per year. 20 years equals 40% of high-3 pay. To partially offset this, DoD contributes 1% of base pay into the Thrift Savings Plan automatically and matches up to 4% of TSP contributions after 2 years of service. The TSP balance is portable: if you separate before 20 years, you keep it. The defined benefit cliff vesting still applies.
For a career servicemember who stays 20-plus years, BRS produces a smaller monthly retirement check than legacy. The TSP account partially offsets this, but most analyses show BRS is somewhat less generous for full-career servicemembers. BRS was designed to benefit the 83% of servicemembers who separate before 20 years and previously walked away with no retirement benefit at all.
The BRS lump sum option
BRS introduced a lump sum option: at retirement, you can elect to receive 25% or 50% of the present value of your future military retired pay as a lump sum, in exchange for reduced monthly payments until you reach Social Security Full Retirement Age, at which point your monthly pay reverts to the full amount. The lump sum is calculated using a discount rate set by DoD, and most analyses show it is not a favorable trade relative to simply taking the full monthly retirement pay throughout retirement.
Survivor Benefit Plan
The Survivor Benefit Plan costs 6.5% of covered retired pay and provides your surviving spouse with 55% of that amount as an inflation-adjusted monthly annuity for life. SBP is generally a favorable deal compared to commercially purchased annuities providing equivalent survivor protection, particularly because of the COLA feature. If you are married at retirement and decline SBP, your spouse must consent in writing. The election is irrevocable after a one-year window following retirement.
Military retirement and Social Security
Unlike most state public pension systems, military service is Social Security-covered employment. Servicemembers earn Social Security credits throughout their military career. There is no WEP or GPO issue for military retirees, because those provisions only apply to pensions from non-SS-covered employment. Military retirees claim Social Security based on their full earnings record without reduction.