TSP Contribution & Agency Match Calculator (2026)
The Thrift Savings Plan is your most powerful retirement savings account — but only if you understand what the agency is matching and how much you're leaving behind. This calculator shows your employee contribution, every dollar of FERS agency match, and your pre-tax savings — updated for the 2026 IRS limits.
How FERS agency matching works
FERS employees receive two types of TSP contributions from the government, on top of whatever they contribute themselves:1
- Automatic 1% contribution: OPM deposits 1% of your biweekly basic pay into your TSP whether you contribute anything or not. This is subject to a 3-year vesting period (2 years for congressional employees).
- Matching contributions: Dollar-for-dollar on the first 3% of basic pay you contribute; 50 cents per dollar on the next 2% (the 4th and 5th percent). Maximum agency match from this tier: 4% of salary.
| Your contribution | Agency automatic | Agency match | Total agency | Combined total |
|---|---|---|---|---|
| 0% | 1% | 0% | 1% | 1% |
| 1% | 1% | 1% | 2% | 3% |
| 2% | 1% | 2% | 3% | 5% |
| 3% | 1% | 3% | 4% | 7% |
| 4% | 1% | 3.5% | 4.5% | 8.5% |
| 5% | 1% | 4% | 5% | 10% |
| 6%+ | 1% | 4% | 5% | 11%+ |
Contributing above 5% earns no additional agency match — but still builds your retirement balance tax-advantaged. The only reason to stop at 5% is cash flow.
2026 TSP contribution limits
The IRS sets annual limits on how much can be contributed to a TSP account. The limits reset each January 1.2
| Limit type | 2026 Amount | Who qualifies |
|---|---|---|
| Base elective deferral | $24,500 | All TSP participants |
| Standard catch-up | $8,000 | Age 50–59, and age 64+ |
| Super catch-up (SECURE 2.0 §109) | $11,250 | Age 60, 61, 62, or 63 |
| Max (base + super catch-up, ages 60-63) | $35,750 | Age 60–63 |
| Max (base + standard catch-up, age 50–59 / 64+) | $32,500 | Age 50–59, 64+ |
Note: The agency's automatic 1% and matching contributions are not counted against your elective deferral limit. You can contribute the full $24,500 (plus any catch-up) and still receive the full agency match on top.
Traditional TSP vs. Roth TSP: which to use?
Your contribution limit is the same regardless of how you split between traditional and Roth TSP. The difference is when you pay taxes:
- Traditional TSP: Contribution reduces your taxable income today. Withdrawals in retirement are taxed as ordinary income. Best when you expect to be in a lower bracket in retirement than you are today.
- Roth TSP: No current-year tax deduction. Qualified withdrawals in retirement (59½+, 5-year holding) are completely tax-free. Best when you expect the same or higher bracket in retirement — common for early retirees who will do Roth conversions in their 50s, or who expect SS + FERS annuity to push them into a higher bracket.
Many federal employees use a split: enough traditional to stay under an IRMAA threshold, and the rest Roth. See the FERS Roth conversion strategy guide for the early-retirement tax window — the gap between FERS retirement (age 57 MRA) and Social Security eligibility (62 or 67) is often the lowest-bracket window of your career.
Note: The agency's matching contributions always go into the traditional (pre-tax) side of your TSP, regardless of how you direct your own contributions. This is a statutory requirement.
How much should I contribute to TSP?
The right contribution depends on your situation, but here is a widely-applicable framework:
- Minimum: 5% of salary. Anything less is leaving agency match on the table. The FERS agency match at 5% contribution equals an immediate 80% return on dollars 4 and 5 (you put in $1, you get $0.50 back) — no investment will beat that.
- Intermediate: 10–15% of salary (employee only). After maximizing the match, additional contributions compound tax-advantaged. A GS-14 at $155,000 who contributes 15% is putting $23,250/year into the TSP — close to the base limit — plus $7,750 in agency contributions, for $31,000 combined.
- Maximum: hit the IRS limit. If you can afford it and are within 5–10 years of retirement, maxing out the TSP (and using catch-up contributions if eligible) is one of the most effective wealth-building moves available to a federal employee. The TSP's expense ratios of 0.033–0.034% are the lowest of any retirement plan in existence.3
CSRS employees and the TSP
CSRS and CSRS Offset employees can contribute to the TSP and receive the same investment options, but they do not receive agency matching contributions. For CSRS employees, the TSP functions more like a traditional IRA — a supplemental savings vehicle on top of your defined benefit pension, with no employer match. The 2026 contribution limits are identical. Most CSRS employees who are within a few years of retirement should prioritize CSRS Offset reconciliation and then use TSP as the overflow vehicle.
Sources
- TSP.gov — Contribution Types (agency automatic and matching contributions)
- TSP Bulletin 25-3 — 2026 Annual Limits for Contributions
- TSP.gov — Fund Expense Ratios and Performance
- IRS.gov — 401(k) limit increases to $24,500 for 2026 (IR-2025-244)
Contribution limits verified against IRS Rev. Proc. 2025-67 and TSP Bulletin 25-3. Agency match schedule per 5 U.S.C. § 8432. Values current as of June 2026.
TSP strategy is more than contribution math
The right TSP allocation, Roth vs. traditional split, and withdrawal sequencing in retirement depend on your full picture — FERS annuity, Social Security timing, FEHB premiums, and tax bracket management. A federal-benefits specialist can model your specific scenario, including the Roth conversion window between your FERS retirement date and age 62, and the IRMAA cliff implications of your TSP balance.
FederalEmployeeAdvisorMatch connects you with fee-only advisors who specialize in FERS, TSP, and federal retirement benefits — no commission, no product sales.
FederalEmployeeAdvisorMatch is a referral service, not a licensed advisory firm. We may receive compensation from professionals in our network. Content is for informational purposes only and does not constitute financial, tax, legal, or investment advice.