Military Retirement Calculator: Project TSP Growth and Pension
Military retirement combines two income streams that civilian workers rarely have together: a defined-benefit pension based on years of service and a Thrift Savings Plan (TSP) that works like a 401(k) — and the Blended Retirement System (BRS), introduced in 2018 by the Department of Defense, changed the terms for most service members entering after January 1, 2018. Use the calculator above to project your TSP growth, then add your pension estimate below to see the full picture.
How it's calculated
This calculator projects your TSP balance — the defined-contribution side of military retirement. Enter your current TSP balance, monthly contributions (your own plus any BRS matching), expected return, and your target separation age.
For the pension side, use the formula that applies to your plan. Under the legacy High-3 system: pension = 2.5% × years of service × average of your three highest-pay years. A 20-year retiree receives 50% of High-3 pay. Under BRS: pension = 2.0% × years of service × High-3 average, plus a government TSP match of up to 5% of basic pay after three years of service, plus a one-time continuation pay bonus at the midpoint. For general retirement projection, see the retirement savings calculator.
A worked example
A service member enters under BRS at age 22, separates at age 42 with exactly 20 years of service and a High-3 average base pay of $72,000 per year. Legacy pension would have been 50% × $72,000 = $36,000 annually ($3,000/month). Under BRS, pension is 40% × $72,000 = $28,800 annually ($2,400/month). However, over 20 years of TSP contributions at $500/month with a 5% employer match ($300/month = $800/month total) at 7% return, the TSP balance at separation is approximately $500,000. If that TSP is withdrawn at 4%, it provides $20,000/year — bringing BRS total income to $48,800, compared with legacy-only $36,000.
Common mistakes to avoid
- Forgetting the 20-year cliff on the legacy High-3 plan. Under legacy rules, separating before 20 years of service means zero pension — you lose the entire defined-benefit, no matter how many years you served. The BRS was designed specifically to fix this cliff for the modern force.
- Not capturing the full BRS TSP match. BRS provides automatic 1% TSP contribution from the government after 60 days, then a dollar-for-dollar match on the next 3% and 50 cents on the next 2% after three years — a total of up to 5% matching. Service members who do not opt in above the 1% auto-contribution leave free money behind.
- Using current base pay instead of High-3 average. The pension formula uses the average of your three highest consecutive annual base-pay years, not your final pay. Late promotions can shift this number meaningfully.
- Ignoring COLA adjustments. Military pensions are adjusted annually for cost-of-living increases tied to the Consumer Price Index, per Department of Defense policy. This inflation protection is a significant advantage over many civilian pensions.
- Overlooking the Survivor Benefit Plan (SBP). Without enrolling in SBP, your pension stops at death and your surviving spouse receives nothing. SBP covers up to 55% of your retirement pay at a premium, and the election window closes at retirement.
Frequently asked questions
What is the difference between the legacy High-3 plan and BRS?
Under the legacy High-3 plan, a 20-year retiree receives 2.5% × years of service × High-3 average pay (50% at 20 years), with no TSP matching and no benefit at all for those who leave before 20 years. Under BRS, the pension multiplier drops to 2.0% (40% at 20 years), but the government provides up to 5% TSP matching after three years of service, a continuation pay bonus, and service members who leave before 20 years keep their TSP balance plus any vested matching.
What happens to my TSP if I separate before 20 years under BRS?
Under BRS, a service member who leaves before 20 years receives no pension but keeps their entire TSP balance, including vested government matching contributions. Government matching vests after two years of service. This is the key BRS design feature: it extends retirement benefits to the roughly 80% of service members who historically left before the 20-year mark and received nothing under the legacy plan.
How much does the government match in the TSP under BRS?
After 60 days of service, the government automatically contributes 1% of basic pay to your TSP. Beginning in your fourth year of service, the government also matches your contributions: dollar-for-dollar on the first 3% you contribute, and 50 cents per dollar on the next 2%. To capture the full 5% match, you must contribute at least 5% of your basic pay.
Can I access my TSP before age 59½ without penalty as a military retiree?
Possibly. If you separate from service in the year you turn 55 or later, you may qualify for the Rule of 55, which waives the 10% early withdrawal penalty on TSP distributions. Additionally, combat-zone tax exclusion rules may apply to contributions made during qualifying deployments. Consult IRS Publication 590-B and your TSP plan documents for specifics.
What is the Survivor Benefit Plan and should I elect it?
The Survivor Benefit Plan (SBP) is a Department of Defense insurance program that continues up to 55% of your retirement pay to a surviving spouse after you die. Premiums are roughly 6.5% of the covered base amount. Without SBP, your military pension stops at death. The election must be made at retirement; you cannot add it later. For most married retirees, SBP is worth evaluating carefully against commercial life insurance alternatives.