Project your TSP balance with the FERS automatic 1% and agency match, the 2026 contribution limits and catch-ups, and a traditional vs Roth comparison
Updated October 2026
For FERS employees, the agency puts in an automatic 1% of basic pay every pay period, even if you contribute nothing. It then matches your own contributions: the first 3% of pay dollar for dollar and the next 2% at 50 cents on the dollar. Contributing 5% therefore brings in 5% of agency money, 10% in all. The projection adds a full year of contributions at the end of each year and grows the balance at the return you assume: balance = today × (1 + r)years + yearly total × ((1 + r)years − 1) ÷ r.
Worked example. A GS-9 step 1 in the Rest of U.S. earns $61,722 in 2026 (OPM). At 5% the employee puts in $3,086 a year. The agency adds $617 automatically and $2,469 in matching, $3,086 in all. That is $6,172 a year. Over 30 years at an assumed 6% a year, that grows to about $487,963: $243,981 from the employee’s money and $243,981 from the agency’s. Contributing nothing would still build about $48,796 from the automatic 1% alone.
| You contribute | Agency automatic | Agency match | Total going in (% of pay) |
|---|---|---|---|
| 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% |
| Rule | 2026 | Source |
|---|---|---|
| Your contributions (elective deferrals, traditional + Roth) | $24,500 | IRS Pub 560 |
| Catch-up, age 50 or older | $8,000 | IRS Pub 560; TSP.gov |
| Catch-up in the years you turn 60, 61, 62 or 63 | $11,250 | IRS Pub 560; TSP.gov |
| All contributions including agency money (415(c)) | $72,000 | IRS Pub 560 |
| Roth catch-up for higher earners | From Jan. 1, 2026, catch-ups must be Roth if your prior-year wages topped the IRS threshold ($150,000 in 2025, indexed) | TSP.gov |
| Agency money | Not counted against your $24,500; always deposited to the traditional balance | TSP fact sheet TSPFS7; TSP.gov |
| Uniformed services | BRS members who began on or after Jan. 1, 2018 get matching after two years of service; CSRS and non-BRS members get none | TSP.gov |
The automatic 1% is subject to vesting, meaning you must work a minimum time before you own it. Matching stops once your own contributions reach the annual limit, so if you would hit $24,500 early in the year, spread your contributions to keep the match in every pay period.
| Choice | You put in a year | Agency puts in | Total a year | Balance after 30 years |
|---|---|---|---|---|
| FERS, 5% (default), 6% return | $3,086 | $3,086 | $6,172 | $487,963 |
| FERS, 3% | $1,852 | $2,469 | $4,321 | $341,574 |
| FERS, 1% | $617 | $1,234 | $1,852 | $146,389 |
| FERS, 0% (automatic 1% only) | $0 | $617 | $617 | $48,796 |
| FERS, 10% | $6,172 | $3,086 | $9,258 | $731,944 |
| FERS, 5%, 4% return | $3,086 | $3,086 | $6,172 | $346,167 |
| FERS, 5%, 8% return | $3,086 | $3,086 | $6,172 | $699,207 |
| CSRS, 5% | $3,086 | $0 | $3,086 | $243,981 |
The return is your assumption, not a TSP forecast. The fund you choose (G, F, C, S, I or an L Fund) and market history decide what you actually earn, so compare a low, middle and high rate. The gap between 4% and 8% over 30 years is larger than the gap between contributing 5% and 10%.
Traditional contributions come out of pay before income tax, and the whole withdrawal is taxed later. Roth contributions are taxed now, and the contributions and earnings come out tax-free once 5 years have passed since January 1 of the year of your first Roth contribution and you are 59½ (or disabled or deceased). If your tax rate in retirement equals your rate today, the two end up the same after tax. Roth wins if your rate will be higher later, traditional if it will be lower. Agency contributions always go to the traditional balance, whichever you choose.
It assumes level pay, contributions made once a year, a constant return and no withdrawals or loans. It does not model pay raises, step increases, fund choice, fees, vesting forfeitures if you leave early, or the timing of the Roth catch-up rule. It also leaves out taxes on withdrawals beyond the flat rate you enter and required minimum distributions. It is not investment or tax advice. Use TSP.gov’s own calculators and your leave and earnings statement for your account, and talk with your agency’s benefits office or a financial adviser for retirement decisions.