Tsp Matching Calculator
If you are a FERS employee contributing less than 5% of your basic pay to the Thrift Savings Plan, you are handing money back to the government every payday. The agency match is worth up to 5% of your pay: an automatic 1% plus matching on your first 5% of contributions. This TSP matching calculator shows exactly how much agency money your contribution rate earns, per year and per paycheck, and what you leave on the table below 5%.
It also flags the trap that costs feds the match even at high contribution rates: front-loading contributions so they stop before year-end. For the bigger retirement picture, our federal employee retirement calculator combines the match with your FERS pension estimate.
Estimate based on 5 U.S.C. 8432. The match applies per pay period; CSRS and non-BRS members receive no agency contributions.
Quick Answer
On $85,000 of basic pay with a 3% contribution, you put in $2,550/year and your agency adds $3,400/year (1% automatic + 3% match), for $5,950 total. Raising your contribution to 5% captures the full match: $4,250 in agency money, $850 more per year you are currently leaving on the table.
The short version
- 5% is the magic number: contribute 5% and the agency puts in 5% (1% automatic + 4% match). Every point below 5% leaves free money behind.
- The match is per paycheck: contribute unevenly and max out early, and the paychecks with no contribution earn no match.
- CSRS gets nothing: the automatic 1% and the match are FERS/BRS benefits. CSRS employees and non-BRS service members are excluded by law.
- The automatic 1% vests: it is yours after 3 years of FERS service (2 for some positions), even if you contributed nothing.
Worked example, run through the real tool
Pre-filled values: $85,000 basic pay, 3% contribution, FERS.
Your contribution: $85,000 x 3% = $2,550/year ($98.08/paycheck). Agency automatic: $85,000 x 1% = $850. Agency match: first 3% dollar-for-dollar = $2,550. Total agency: $3,400/year (4.0% of pay). Combined into TSP: $5,950/year. Press Calculate to reproduce every figure, including the full 0%-to-5% comparison table.
Now set the contribution to 5%: your $4,250 earns $850 automatic + $3,400 match = $4,250 in agency money. The gap between 3% and 5% is $850/year of free money, which at 6% growth over 30 years compounds to roughly $67,200. That is the true price of contributing 3% instead of 5%.
How the match formula works
The formula comes from 5 U.S.C. 8432: the agency contributes 1% of basic pay automatically, then matches employee contributions on the first 5% of pay, dollar-for-dollar on the first 3% and fifty cents on the dollar on the next 2%. Above 5%, there is no additional match, though contributing more is still worthwhile for the tax benefit and growth.
The front-loading trap
The match is computed each pay period, not once a year. If you contribute heavily early in the year and hit the elective deferral limit ($24,500) by October, the remaining paychecks have no employee contribution, and paychecks with no contribution earn no match. Spreading the same dollars evenly across all 26 pay periods captures the full match.
The fix is simple: divide your annual target by the number of remaining pay periods and set that per-paycheck amount. The tool’s per-paycheck figure ($98.08 in the example) is the number to actually elect.
Beyond 5%: still worth it
Capturing the match is step one; it is not the ceiling. Contributions above 5% get no additional match, but they still reduce your taxable income (traditional) or build tax-free growth (Roth), and every extra dollar compounds for decades. The 2026 elective deferral limit is $24,500, plus catch-up contributions if you are 50 or older. To see what the full contribution plus match becomes over your career, run the combined annual figure through our investment growth calculator, and watch how raises accelerate it with the compound salary increase calculator.
What competing calculators miss
Most TSP tools project account growth and bury the match as one input line. Calculatorov’s TSP calculator does that; planwellfp explains the match well but never prices your personal shortfall; the federal blogs (fedsmith, federalwarrior) write excellent explainers with no interactive math at all.
This page is built around the one question that matters most: how much free money does my contribution rate earn? It prices the automatic 1% separately from the match, shows the per-paycheck figure to elect, tables every rate from 0% to 5% so the cost of each point is visible, and compounds the shortfall over 30 years so “just $850 a year” reads as the $67,200 it really is.
Frequently asked questions
Up to 5% of your basic pay: an automatic 1% agency contribution plus matching on your first 5% of contributions (100% on the first 3%, 50% on the next 2%). Contribute 5% and the agency puts in 5%.
No. The 1% agency automatic contribution is deposited whether or not you contribute anything. It vests after 3 years of FERS-covered service (2 years for some positions); your own contributions are always immediately vested.
You get no additional match beyond the 5% agency total, but extra contributions still earn the tax benefit and compound for decades. Many feds contribute well above 5% up to the annual elective deferral limit.
Yes. The match is computed per pay period, so if you hit the annual contribution limit early, later paychecks have no contribution and earn no match. Spread contributions evenly across all pay periods to capture the full match.
No. CSRS employees receive no agency automatic or matching contributions. The match is a FERS (and Blended Retirement System) benefit only.
Service members under the Blended Retirement System get the same automatic 1% and matching as FERS employees. Those under the legacy system do not receive matching contributions.
Basic pay only, which excludes overtime, bonuses, and allowances. Locality pay is part of basic pay for this purpose.
The match is earned by your contributions whether they are traditional or Roth, but all agency contributions (automatic and matching) go into your traditional TSP balance, not the Roth balance.
The 2026 elective deferral limit is $24,500, with additional catch-up contributions allowed at 50 and older. Agency contributions do not count against your elective deferral limit.
References
- Thrift Savings Plan. "Agency/Service Automatic (1%) and Matching Contributions." TSP.gov: Agency/Service Automatic and Matching Contributions (Accessed Oct 19, 2026).
- Thrift Savings Plan. "Contribution Limits." TSP.gov: Contribution Limits (Accessed Oct 19, 2026).
- Thrift Savings Plan. "Contribution Types." TSP.gov: Contribution Types (Accessed Oct 19, 2026).
- Legal Information Institute, Cornell Law School. "5 U.S. Code Section 8432 - Contributions." Cornell LII: 5 U.S.C. Section 8432 (Accessed Oct 19, 2026).
- U.S. Office of Personnel Management. "Federal Employees Retirement System (FERS)." OPM: Federal Employees Retirement System (Accessed Oct 19, 2026).
- Thrift Savings Plan. "Vesting." TSP.gov: Vesting (Accessed Oct 19, 2026).