TSP Calculator 2026
Project your Thrift Savings Plan balance at retirement. Enter your contributions, agency match, and years to go. See the balance breakdown, monthly income estimate, and Traditional vs Roth split.
How this calculator works and the math behind it2026 Employee Limit
$23,500
Catch-Up (Age 50+)
+$7,500
Max with Agency Contributions
$70,000
How TSP works
The Thrift Savings Plan is a defined contribution retirement account for federal employees and members of the uniformed services. You contribute from each paycheck, the government adds to it, and the balance grows tax-deferred (or tax-free with Roth) until retirement.
For FERS employees, the government match is the most valuable piece of the benefit package that most people underuse. Here's the actual structure:
- 1% automatic contribution from your agency, deposited every pay period regardless of whether you contribute anything
- Dollar-for-dollar match on the first 3% of your salary you contribute
- 50-cent match on the next 2% of salary
Contribute 5% and you get 5% from the agency. That's a 100% return on the first 5% before the money hits the market. Contributing less than 5% means leaving agency money uncaptured.
The 1% automatic contribution vests immediately. Matching contributions vest after 3 years of federal service.
TSP funds explained
TSP has five core funds and a family of target-date L Funds. Each is an index fund with expense ratios around 0.04%, far cheaper than most mutual funds in a private-sector 401(k).
The G Fund invests in special Treasury securities that earn a return tied to longer-term Treasuries with no risk of losing principal. Historically around 3-4% annually. It's safe, but over a 25-year accumulation horizon that safety has a real opportunity cost in foregone growth.
The C Fund tracks the S&P 500. The average annual return since the fund's inception in 1988 is roughly 10%. There will be years it drops 30%, but over long time horizons, equity exposure is how TSP balances compound into real money.
The S Fund covers small- and mid-cap U.S. stocks not in the S&P 500: higher volatility, higher long-term expected returns than C. The I Fund tracks international markets in developed economies. Both serve a diversification role when held alongside C.
The F Fund tracks the Bloomberg U.S. Aggregate Bond Index. It carries more interest rate risk than G (bond prices fall when rates rise) but has returned more over time and moves differently than stocks, which reduces portfolio volatility.
L Funds are lifecycle funds for specific retirement windows: L 2030, L 2035, out to L 2065, plus L Income for people already drawing down. They automatically shift toward more conservative allocations as the target date approaches. The allocations are reasonably conservative by default, which works well for people who don't want to think about rebalancing.
Traditional vs Roth TSP
Traditional TSP contributions reduce your taxable income now. You pay income tax on withdrawals in retirement. If your tax rate in retirement is lower than today, Traditional wins. That's the common assumption for federal employees near their salary peak.
Roth TSP contributions are made after tax. Qualified withdrawals in retirement are completely tax-free, including all the growth. If your tax rate in retirement is higher than today, or you want tax diversification, Roth has a real advantage.
One wrinkle worth knowing: agency contributions always go into your Traditional account regardless of your Roth election. You can't direct the match to Roth. Even if you contribute 100% to Roth TSP, you'll have some Traditional balance from agency contributions.
For most mid-career federal employees, a split makes sense. Put enough in Traditional to reduce current tax exposure while building a Roth balance that gives you flexibility in retirement. The exact ratio depends on your current bracket and your view on future tax rates.
TSP at retirement
At retirement you have several options. You can leave your TSP where it is and take withdrawals on your own schedule, subject to required minimum distributions starting at age 73. You can roll to an IRA, which gives you more investment choices. Or you can buy a TSP annuity that pays monthly income for life.
The TSP annuity converts your balance to a guaranteed monthly payment. MetLife is the current provider. It makes sense for people who worry about outliving their money, but once you annuitize you lose access to the principal, and the payout rate depends on interest rates at purchase.
RMDs from Traditional TSP start at age 73 under current law. Roth TSP was subject to RMDs until the SECURE 2.0 Act eliminated that requirement in 2024. Rolling your Roth TSP to a Roth IRA before RMDs become relevant avoids the issue entirely and keeps more options open.
The 4% rule used in this calculator comes from the Trinity Study: withdrawing 4% of your balance in year one, then adjusting for inflation each year, has had a 95%+ historical success rate over 30-year retirement periods. In low-return environments or longer retirements, 3-3.5% is more conservative. If you have a FERS pension and Social Security covering most of your fixed expenses, you may not need to draw that much from TSP at all.
Frequently asked questions
What is the TSP contribution limit in 2026?
The employee elective deferral limit is $23,500. Employees age 50 and older can add $7,500 in catch-up contributions, for a total of $31,000. When you factor in agency contributions, total annual additions to your account can reach $70,000.
How much does the government match TSP contributions?
FERS employees get a 1% automatic agency contribution deposited every pay period regardless of what they contribute. The agency also matches dollar-for-dollar on the first 3% of salary, then 50 cents on the next 2%. Contribute 5% and you capture the full 5% match. Contribute less and you leave money uncaptured.
Which TSP fund should I invest in?
The C Fund (S&P 500 index) has historically returned around 10% annually and is the core holding for most people in the accumulation phase. The G Fund averages 3-4% with no principal risk, which makes it appropriate for near-retirees or as a stabilizer in a diversified allocation. L Funds automatically shift allocations as you approach your target date and work fine as a one-fund solution.
Can I withdraw my TSP at 55?
FERS and CSRS employees who separate from federal service at age 55 or older can take TSP withdrawals without the 10% early withdrawal penalty. This is specific to TSP under the IRS rules for government plan distributions from separating employees. For most other accounts, you have to wait until 59.5.
What happens to TSP if I leave federal service?
Your TSP account stays open and keeps growing. You can leave it there, roll to an IRA or another eligible employer plan, or take distributions. You cannot make new contributions once you leave federal service. Leaving it in TSP keeps access to the G Fund and the extremely low expense ratios, which is a real advantage. Rolling to an IRA gives you more investment options and no RMD requirement on Roth balances.