Start with a verified contribution amount
The IRS explicitly includes the federal Thrift Savings Plan in its 2026 employee elective-deferral limit of $24,500. Its current guidance also identifies the ordinary $8,000 age-50 catch-up and the replacement $11,250 amount for eligible participants attaining ages 60–63 in 2026.
| Age at year-end | Base | Catch-up | Employee deferrals |
|---|---|---|---|
| Under 50 | $24,500 | $0 | $24,500 |
| 50–59, or 64+ | $24,500 | $8,000 | $32,500 |
| 60–63 | $24,500 | $11,250 | $35,750 |
IRS Notice 2025-67, pages 1–2; reviewed October 25, 2026. The ages-60–63 catch-up replaces the usual age-50 amount.
These amounts are verified against IRS Notice 2025-67, pages 1–2, the November 13, 2025 IRS release and catch-up guidance, updated May 7, 2026. Reviewed October 25, 2026. Compensation, plan rules and other covered deferrals can affect what is available to a particular participant.
The employer field is a dollar assumption
Enter an annual employer contribution only after checking your own benefits and payroll records. The tool begins at zero and does not calculate a matching percentage, automatic contribution, vesting date or catch-up payroll election. It does not determine benefits under FERS, CSRS, BRS or another service-specific arrangement.
A check that needs no market forecast
Suppose the starting account is $100,000, your contribution is $12,000 each year and a verified employer amount is $4,000 a year. At zero return over ten years, total new deposits are $160,000 and the account reaches $260,000. The $4,000 is an invented example amount, not a stated TSP benefit.
Use the starting balance you intend to model, and confirm what any unvested amounts mean in your circumstances. The calculator does not automatically remove them or assess whether they will become yours.
Account growth is different from spendable value
The projected account balance is before any withdrawal tax. Traditional and Roth balances are not compared after tax, and the tool does not determine qualified Roth distribution status. Keeping the tax treatment separate avoids labeling the entire displayed balance as spendable retirement income.
Beginning in 2026, the IRS describes required Roth catch-ups where prior-year wages with the plan sponsor exceeded $150,000. That threshold uses prior-year wages with the sponsor, not household income. Confirm how the rule affects your elections; the growth model does not calculate its payroll or tax consequences.
Use return and inflation as separate assumptions
The annual return is an effective rate converted to an equivalent monthly rate. Each annual contribution is divided into twelve equal deposits at month-end. The account receives those deposits and the same modeled monthly growth for the entire horizon.
The green line is nominal account value. The brass line discounts it by your chosen inflation assumption. A $260,000 nominal endpoint has the same purchasing power as $260,000 today only when modeled inflation is zero. Change the inflation input to see that distinction without changing the nominal investment path.
This is not a TSP fund-performance tool. It contains no fund prices, historical return series, allocation recommendation or Lifecycle Fund simulation. Fees should already be reflected in the return you enter, and a negative rate is permitted for scenario comparison.
From saving to withdrawing
Annual deposits stay fixed even as the participant gets older. Future statutory limits, pay changes, employer benefits and tax rules are not forecast. The 2026 limit panel is a dated reference next to a separate multi-year scenario.
When you want to include spending, use the investment calculator with withdrawals. To solve an amount for a selected retirement duration, use the monthly withdrawal calculator. The 403(b) and 457(b) pages explain the separate scopes of those plans.
Questions about this calculation
Does this TSP calculator assume a matching percentage?
No. The employer contribution starts at zero. Enter a verified annual employer amount from your own records or administrator; this page does not determine FERS, CSRS, BRS or service-specific benefits.
Are traditional and Roth TSP contributions separate employee limits?
No. The 2026 employee elective-deferral reference is shared across the covered pre-tax and designated Roth deferrals. The tool projects an account value before any withdrawal tax, not an after-tax comparison between account types.
Does the calculator model individual TSP funds?
No. It applies your chosen constant return to the whole entered balance and future deposits. It does not retrieve fund prices, choose an allocation, simulate historical performance or model a Lifecycle Fund.
Will contribution amounts rise automatically in future years?
No. Both employee and employer annual dollar inputs remain constant. The 2026 age setting changes only the current standard reference, not the future contribution stream.
Sources and boundaries
IRS limit and catch-up sources above were reviewed October 25, 2026. No current TSP-specific matching schedule, fund return, vesting rule or service-specific contribution exception was verified for this tool, so none is hardcoded.
Read the projection method and financial disclaimer. The examples are educational arithmetic, not a recommendation to contribute a particular amount or choose an investment.