Last Updated: November 4, 2026 Reading Time: 8 min

If you want to max out your TSP in 2026, stop counting paydays left and count the paychecks your election can still reach. The 2026 limit on your own TSP contributions is $24,500. Your new election is only guaranteed for the first full pay period after your agency gets it, so a change today may miss your next check or two.

How Many 2026 Paychecks Your Election Can Still Reach

You can change your election at any time, through your agency's payroll system, not through TSP. The start date is the catch. This table shows the guaranteed reach for an election your agency receives in each window.

Payroll provider 2026 pay dates left (official) Received Nov. 1 to 14 Received Nov. 15 to 28 Received Nov. 29 to Dec. 12
GSA 5: Nov. 10, Nov. 25, Dec. 9, Dec. 23, Dec. 31 3 2 1
NFC 4: Nov. 12, Nov. 26, Dec. 10, Dec. 24 2 1 0
IBC 4: Nov. 10, Nov. 24, Dec. 8, Dec. 22 2 1 0

These are outer limits under the regulation, as of November 4, 2026. Your agency may apply an election sooner, which adds a check. An internal payroll cutoff could take one away. If IBC pays you, confirm the dates on your LES.

If NFC or IBC pays you, at the regulation's latest permitted date an election received November 29 to December 12 reaches your first 2027 check. Earlier implementation may still reach a 2026 check. If NFC pays you, the check for the period ending Dec. 26 pays Jan. 7, 2027 and counts toward 2027. If GSA pays you, the Dec. 31 check counts toward 2026. Our 27 pay periods post covers that extra GSA check.

DoD civilians: count your remaining paydays on your myPay calendar. We couldn't retrieve DFAS's pay calendars, so they aren't in the table. The same goes for military pay dates.

The limit follows the year your paycheck is dated, not the year you worked the hours. Use your LES year-to-date, not your TSP balance, because posting can lag.

The Math: What to Elect for the Rest of 2026

Take your limit, subtract what you've put in and what's already locked in, divide by the paychecks your election can reach, and round up to the next dollar.

"Locked in" means the dollars coming out of checks paid before the new election starts. Traditional and Roth count together toward the same $24,500. Your agency's 1% and match do not count toward your $24,500. Elections are whole dollars or whole percentages, which is why you round up.

Room left 2 checks 3 checks 4 checks 5 checks
$1,000 $500 $334 $250 $200
$2,000 $1,000 $667 $500 $400
$3,000 $1,500 $1,000 $750 $600
$4,000 $2,000 $1,334 $1,000 $800
$5,000 $2,500 $1,667 $1,250 $1,000

Each amount is room left divided by checks, rounded up to the next dollar. Where it doesn't divide evenly, the last check runs a dollar or two lower. Payroll stops your contributions at the limit (for 50 or older, the combined limit with catch-up). Plan the smaller last check yourself, because we couldn't confirm how each payroll handles a final partial deduction.

Example, under 50, paid by NFC, electing $1,000 now. You've put in $20,000 and the Nov. 12 and Nov. 26 checks are locked in for $2,000. That leaves $2,500 across the two checks your election reaches if it starts after those, so elect $1,250.

A large last-minute election can run out of pay. If it does, traditional comes out before Roth.

Don't Let the Year-End Push Cost You the Match

FERS and BRS participants have a second number to watch. The match is figured one pay period at a time: dollar for dollar on the first 3% of basic pay, 50 cents on the dollar for the next 2%. To get the full match, every paycheck needs at least 5% of basic pay. Below that, that paycheck's match shrinks. The TSP does not true up your match at year-end.

If you're under 50, this cuts both ways:

  • Front-loaded too much? Reach the limit early and your agency match stops too, for the rest of the year. Your agency's automatic 1% keeps coming after you hit the limit.
  • Too little room left? Spreading $600 over four checks of $150 for someone with $3,963.42 in biweekly basic pay earns $134.45 a check, $537.80 in all. Two checks of $300 earn the full $158.54 each, $317.08 in all. More checks with some contribution beat fewer checks at the full rate.

The example's pay is GS-13 step 5 base pay before locality, for illustration only. Use your own basic pay.

On FERS at 50 or older, reaching $24,500 early does not cost you the match. It stops only when you also use up the catch-up. BRS members lose the match the same way: a period with no contribution has no match.

Catch-Up and Roth: The Year-End Surprise on Your Paycheck

If you are 50 or older by Dec. 31, 2026, you can add $8,000 in catch-up, for $32,500 in all. If you turn 60, 61, 62 or 63 in 2026, your catch-up limit is $11,250, not $8,000, for $35,750 in all.

At 50 or older there is no separate catch-up form. Past $24,500, contributions count as catch-up automatically. Your age on Dec. 31 sets your limit for the whole year. Turn 64 in 2026 and you drop back to the $8,000 catch-up.

If your prior-year Social Security wages were over the IRS threshold, your catch-up must be Roth. For 2026, the test is more than $150,000 of 2025 Social Security wages from the employer sponsoring the plan. Confirm your federal payroll wage total. Earlier Roth contributions count toward the Roth catch-up requirement. For affected participants, remaining spillover must be Roth once traditional contributions reach $24,500.

For most people payroll makes the Roth switch automatically. Check your LES to confirm yours. If your traditional contributions turn into Roth catch-up late in the year, expect a smaller take-home on those checks. Your match still goes in as traditional money, even when your catch-up is Roth. Our mandatory Roth catch-up post has more on who it hits.

Outside 401(k)s and the Excess-Deferral Repair

The TSP can't see money you put in anywhere else. If you also deferred to a 401(k) in 2026, such as at a job before you joined or a second job, those dollars count against the same $24,500. Subtract them yourself. Guard and Reserve members with a civilian account get one limit across both accounts, not two.

If you go over, fix it fast:

  • April 15, 2027 is the IRS's outer deadline for 2026 excess deferrals, and it does not move if you extend your tax return. Your plan can set an earlier date, so do not wait.
  • Ask the ThriftLine early in 2027 for TSP's 2026 excess-deferral request deadline.
  • Leave an excess in place and you pay tax on it twice: in the year contributed and again when it comes out.
  • A timely fix keeps you from double tax. The earnings on the excess are taxable in the year they are paid out.

Uniformed Services and Year-End Bonuses

Service members need a basic-pay election to contribute from special or incentive pay. Catch-up can't come from bonus or special pay, and from combat-zone tax-free pay it can only be Roth.

A year-end bonus contribution earns no match and can use up your limit, so basic-pay checks after it can lose their match. Per TSP's bulletin, tax-free combat-zone traditional money doesn't use up your $24,500 but does count toward $72,000. The separate cap on total additions is $72,000 in 2026.

Run Your Numbers

Enter your salary, current election, age bracket and pay periods in our TSP contribution calculator to see a per-pay-period amount before you change your election. The tool assumes your current election applied through every elapsed period, so if you changed it this year, use the LES-based formula above.

The 2027 limits aren't out yet: we found no published 2027 limits as of November 4, 2026. When it does, our 2027 limit post gets the numbers and the January election to make.

Frequently Asked Questions

When is it too late to change my 2026 TSP contribution?

It depends on your payroll provider. If NFC or IBC pays you, at the regulation's latest permitted date an election received November 29 to December 12 reaches your first 2027 check, though earlier implementation may still reach a 2026 check. On GSA's calendar an election received by December 12 still reaches one check.

Which paycheck is my last for 2026 TSP contributions?

The limit follows the year your paycheck is dated. If GSA pays you, the Dec. 31 check counts toward 2026. If NFC pays you, the last 2026 payday is Dec. 24, and the check for the period ending Dec. 26 pays Jan. 7, 2027 and counts toward 2027.

Does hitting the TSP limit early stop my agency match?

Under 50 on FERS or BRS, yes. Reach the limit early and your agency match stops too, for the rest of the year. On FERS at 50 or older, reaching $24,500 early does not cost you the match. It stops only when you also use up the catch-up. Your agency's automatic 1% keeps coming.

Do I need a separate election for TSP catch-up contributions?

No. At 50 or older there is no separate catch-up form. Past $24,500, contributions count as catch-up automatically.

What happens if I go over the limit with a 401(k) and the TSP?

Those dollars count against the same $24,500, and you have to catch it yourself. April 15, 2027 is the IRS's outer deadline for 2026 excess deferrals, and your plan can set an earlier date, so do not wait.

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