TSP Calculator — Thrift Savings Plan Projector (2026)

The Thrift Savings Plan offers five individual investment funds:

• G Fund (Government Securities): Invests in short-term U.S. Treasury securities. Lowest risk, lowest return. Your principal is guaranteed by the U.S. government. Historical average: ~2.4%/year.
• F Fund (Fixed Income): Tracks the Bloomberg U.S. Aggregate Bond Index. Low-to-moderate risk. Historical average: ~4.5%/year.
• C Fund (Common Stock): Tracks the S&P 500 index. Moderate-to-high risk. Historical average: ~10.5%/year. The most popular TSP fund.
• S Fund (Small Cap): Tracks a broad U.S. stock market index excluding the S&P 500. Higher risk, higher potential return. Historical average: ~10.0%/year.
• I Fund (International): Tracks international developed-market stocks. Provides global diversification. Historical average: ~7.5%/year.

The TSP also offers Lifecycle (L) funds that automatically rebalance from aggressive to conservative as you approach your target retirement date.

Under the Blended Retirement System (BRS), the government contributes to your TSP in two ways:

1. Automatic 1%: The DoD automatically contributes 1% of your basic pay to your TSP, regardless of whether you contribute anything. This starts at 60 days of service and is vested after 2 years.
2. Matching contributions: Starting after 2 years of service (through 26 years), the government matches:
   • Dollar-for-dollar on the first 3% you contribute
   • 50 cents on the dollar for the next 2% you contribute

To get the maximum 5% government contribution (1% auto + 4% match), you need to contribute at least 5% of your basic pay. Contributing less than 5% means you are leaving free money on the table.

For 2026, the IRS limits are:

• Elective deferral limit: $24,500 (your Traditional + Roth contributions combined)
• Catch-up contributions (age 50+): Additional $8,000 (total $32,500)
• Annual addition limit (Section 415(c)): $72,000 (includes government matching)

Tax-exempt combat zone pay can be contributed above the elective deferral limit, up to the $72,000 annual addition limit.

Traditional TSP: Contributions reduce your taxable income today. You pay income tax on withdrawals in retirement.

Roth TSP: Contributions are made with after-tax dollars. Qualified withdrawals in retirement (age 59½ and 5 years after first contribution) are completely tax-free — including all investment growth.

For most military members, Roth TSP is generally advantageous because:

• Military pay (especially junior enlisted) is often in a low tax bracket
• BAH and BAS are already tax-free, reducing your taxable income further
• Tax-free growth over 20-30 years can be substantial
• Future tax rates may be higher than current rates

Under BRS, the government automatically contributes 1% plus matches up to 4% more (dollar-for-dollar on the first 3% you contribute, 50 cents per dollar on the next 2%). Total maximum government contribution is 5% of your basic pay.

Under the legacy retirement system (High-36, Final Pay), there is no government TSP matching.

The 2026 elective deferral limit is $24,500. Members age 50+ can add $8,000 in catch-up contributions. Government matching does not count toward these limits.

Divide your remaining room (the annual IRS elective deferral limit minus what you've already contributed this year) by your monthly basic pay times the months left in the year, then round down to a whole percentage. The Max the Match mode above does this math for you.

Why it matters: BRS matching is deposited each pay period. If you hit the annual limit early, payroll stops your contributions and the up-to-4% match stops with them for the rest of the year — only the 1% automatic contribution continues. Rounding down leaves a small December cushion that keeps you contributing (and matched) through your final paycheck of the year.

There is no single "best" allocation — it depends on your age, risk tolerance, and retirement timeline. Common approaches include:

• Aggressive (young service members): 60% C Fund, 20% S Fund, 20% I Fund
• Moderate: 40% C, 20% S, 20% I, 10% F, 10% G
• Lifecycle funds: Pick the L Fund closest to your expected retirement year and let it auto-rebalance

The default allocation for new TSP accounts is the age-appropriate L Fund.

You can begin withdrawals penalty-free at age 59½, or when you separate from service if you are 55 or older (the "Rule of 55"). Early withdrawals before these ages incur a 10% penalty plus income taxes on Traditional TSP funds.

Roth TSP withdrawals of your contributions are always tax-free. The growth portion is tax-free only if the account has been open 5+ years and you are 59½ or older.