Agency contributions under FERS
| You contribute | Automatic 1% | Match | Total into TSP |
|---|---|---|---|
| 0% | 1% | 0% | 1% |
| 1% | 1% | 1% | 3% |
| 2% | 1% | 2% | 5% |
| 3% | 1% | 3% | 7% |
| 4% | 1% | 3.5% | 8.5% |
| 5% | 1% | 4% | 10% |
Percent of basic pay. The automatic 1% and its earnings are subject to vesting: you keep them after 3 years of civilian service, or 2 years for noncareer Senior Executive Service, Executive Schedule and Schedule C appointees and congressional employees. Matching contributions are yours right away.
Roth or traditional?
Traditional contributions lower your taxes now and are taxed when you take them out. Roth contributions are taxed now and come out tax-free in retirement, if you meet the rules. For the same cost to your paycheck today, the one that wins is simply the one taxed at the lower rate, as long as you're under the IRS limit. At the limit, Roth wins more often, because the same $24,500 holds more after-tax money. The calculator compares them that way. Agency contributions always go into traditional TSP.
2026 limits
$24,500 of your own contributions (traditional and Roth combined). In the year you turn 50 or older you can add a catch-up of $8,000; in the years you turn 60 to 63, $11,250. Starting in 2026, if you earned more than $150,000 in 2025, your catch-up contributions must go in as Roth; the TSP switches them for you. Agency contributions don't count toward these limits. The calculator keeps these limits for later years, so it may cap high earners a little early. The 2027 limits will be announced by the IRS; we'll update this page then.
What this assumes
26 pay periods a year. If you reach the IRS limit before December, your contributions stop and so does your agency's match for the rest of the year, so spread contributions over the whole year. One steady yearly return and pay raise, contributions added at the end of each year, and no loans or withdrawals. Real returns vary year to year. This isn't a forecast or investment advice.
Questions
How much does my agency put in my TSP?
Under FERS, 1% of your basic pay automatically, even if you contribute nothing, plus a match: dollar for dollar on the first 3% you contribute and 50 cents per dollar on the next 2%. Contribute 5% and your agency adds 5%.
Should I choose Roth or traditional TSP?
If you expect a higher tax rate in retirement than now, Roth usually comes out ahead; if lower, traditional does; if the same, they're equal for the same cost to your paycheck. Agency contributions always go into traditional TSP.
What is the TSP contribution limit?
For 2026, $24,500 of your own contributions, plus $8,000 more if you turn 50 or older this year, or $11,250 more if you turn 60 to 63. Agency contributions don't count toward that limit. If you earned more than $150,000 in 2025, your catch-up contributions must be Roth. The 2027 limits will be announced by the IRS.
Updated November 6, 2026. Sources: TSP, What is a contribution?; TSP, Making Contributions; IRS Notice 2025-67 (2026 limits); IRS, Retirement topics - Catch-up contributions. Estimates, not financial, tax or legal advice. Not affiliated with the TSP or the Federal Retirement Thrift Investment Board.