If you work for the federal government, the Thrift Savings Plan is probably the largest retirement asset you will build, and understanding how TSP matching works is the most valuable thing you can learn about it. The plan itself is straightforward once the structure is clear. The difficulty is that the matching formula has two separate parts, and many participants contribute at a level that quietly leaves agency money unclaimed every pay period.
What the Thrift Savings Plan Is
The Thrift Savings Plan, or TSP, is the federal government’s version of a 401(k). Congress created it in the Federal Employees’ Retirement System Act of 1986. It serves federal civilian employees and uniformed services members, including the Ready Reserve, and it is administered by the Federal Retirement Thrift Investment Board.
It is a defined contribution plan. What you eventually receive depends on what you put in, what your agency put in, and what those balances earned along the way. That makes it different from a traditional pension, where the benefit follows a formula based on salary and years of service.
For an employee under the Federal Employees Retirement System, known as FERS, the TSP is one of three parts of the retirement package, alongside the FERS basic annuity and Social Security. It is the part you control, and the part most affected by decisions you make early.
How TSP Matching Works
If you are a FERS participant, your agency contributes to your account in two distinct ways, and the distinction matters.
The first is the Agency Automatic contribution. Your agency deposits an amount equal to 1 percent of your basic pay every pay period whether or not you contribute anything yourself. You do not need to take any action to receive it, though it is subject to vesting rules based on your years of service.
The second is the Agency Matching contribution, and this one does require action. Your agency matches the first 3 percent of basic pay you contribute dollar for dollar. It then matches the next 2 percent at fifty cents on the dollar. Above 5 percent, no additional match is available, though you may still contribute more.
Put the two together and one number is worth memorizing. Contribute 5 percent of your pay, and your agency adds 5 percent, for a total of 10 percent of salary flowing into the account. Contribute nothing, and your agency still adds 1 percent, but the entire 4 percent match goes unclaimed.
Before reading on, try the question below. Most federal employees who miss it miss it in the same direction.
The full schedule published by the TSP looks like this.
| You contribute | Automatic 1% | Agency match | Total into your account |
|---|---|---|---|
| 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% |
| More than 5% | 1% | 4% | Your percentage plus 5% |
One detail catches people who save aggressively. Matching is calculated pay period by pay period, not annually. If you front-load contributions and reach the yearly limit in October, your contributions stop, and the match stops with them for the remaining pay periods. Spreading contributions across all 26 pay periods protects the full match.
Contribution Limits for 2026
The TSP follows the same IRS limits that apply to workplace plans generally. For 2026 the figures are as follows.
- The elective deferral limit, covering your own traditional and Roth contributions combined, is $24,500. Agency contributions do not count toward it.
- Beginning in the year you turn 50, the catch-up limit adds $8,000.
- In the years you turn 60, 61, 62, or 63, the catch-up limit rises to $11,250. It returns to the regular amount the year you turn 64.
A rule that took effect on January 1, 2026 deserves attention. If your prior-year wages exceeded the IRS threshold, which was $150,000 for 2025, any catch-up contributions you make must be designated as Roth. For most participants the switch happens automatically, but it is worth confirming with your payroll office. The TSP explains the mechanics on its contribution types page.
Traditional or Roth Inside the TSP
The TSP accepts both traditional and Roth contributions. Traditional contributions reduce your taxable income now and are taxed when withdrawn. Roth contributions are made with money that has already been taxed, and qualified withdrawals come out tax free.
One point causes recurring confusion. Agency contributions are always traditional, even if every dollar you contribute is Roth. Those agency dollars and their earnings are taxable when you eventually withdraw them.
The Investment Choices
The TSP offers five individual funds: the G Fund of government securities, the F Fund of bonds, the C Fund tracking large United States companies, the S Fund covering smaller companies, and the I Fund covering international stocks. The Lifecycle Funds, known as L Funds, blend those five into a mix tied to a target date and adjust over time. A mutual fund window is available for participants who want access beyond the core lineup.
Administrative and investment expenses in the core funds are among the lowest available in any retirement plan. That cost advantage is one reason many federal employees keep balances in the TSP after leaving federal service rather than rolling everything to an IRA.
What California Federal Employees Should Know
The Sacramento region employs a substantial federal workforce, and the state tax picture is worth understanding early. California does not offer a special exclusion for federal retirement income. If you are a California resident when you take TSP withdrawals, traditional distributions are taxable as ordinary income at the state level as well as federally. Qualified Roth withdrawals are not.
That makes the traditional-versus-Roth decision more consequential for someone who expects to retire in California than for someone who expects to relocate. It is not a reason to choose one or the other by itself, but it belongs in the analysis.
Three Common Missteps
- Contributing below 5 percent. Every percentage point below 5 leaves agency money unclaimed permanently. It cannot be recovered later.
- Reaching the annual limit early. Front-loading stops contributions, and matching stops with them for the rest of the year.
- Leaving the default allocation unexamined. An automatic enrollment default is a starting point, not a decision. It may or may not match your time horizon.
Where to Go From Here
If the question above surprised you, the next step is simple: check your contribution election against the 5 percent threshold, and confirm your contributions are spread evenly across the year. Both adjustments cost nothing and are the highest-value changes most FERS participants can make.
Beyond that, the TSP does not exist in isolation. It sits alongside your FERS annuity, Social Security, and whatever else you have built, and the traditional-versus-Roth question depends on the whole picture. If you would like to walk through how your TSP fits with the rest of your plan, you can schedule a free 30-minute call with Rooney Wealth Management at no cost and no obligation.
The information in this article and the results produced by the tool above are educational and hypothetical in nature. They do not constitute individualized investment, tax, or legal advice, and they are not a guarantee or projection of any particular outcome. Actual results vary based on your specific circumstances, and plan rules and tax law are subject to change. Please consult a qualified financial, tax, or legal professional regarding your own situation. Rooney Wealth Management LLC is a California-registered investment adviser.
