Starting January 1, 2026, a new rule took effect that quietly changed how catch-up TSP contributions work for a specific group of federal employees. If you’re 50 or older and earned above a certain threshold last year, your catch-up contributions are now required to go to your Roth TSP balance, not your traditional balance, whether you elected that or not. This is one of the provisions of SECURE Act 2.0, and here’s what you need to know.
Who the Rule Applies To
The mandatory Roth catch-up requirement applies to you in 2026 if all three of the following are true:
- You will be age 50 or older as of December 31, 2026
- Your Social Security wages from 2025, reported in Box 3 of your 2025 W-2, exceeded $150,000
- You are making catch-up contributions to your TSP this year
The threshold is based on prior-year Social Security wages, not your current salary or your gross pay. Pre-tax TSP contributions you made in 2025 do not reduce the figure in Box 3; Social Security wages are calculated before those deductions. One exception worth noting: if you were newly hired into federal service during 2026 and had no federal wages in 2025, the rule does not apply to you this year.
What Actually Changes
Catch-up contributions are additional money that employees age 50 and older are allowed to contribute to their retirement accounts on top of the standard annual limit. Under normal circumstances, once you hit the standard 2026 elective deferral limit of $24,500, your TSP contributions stop unless you have a catch-up election in place. If you’re subject to the mandatory Roth rule, any contributions beyond that $24,500 limit are automatically redirected to your Roth TSP balance. Your payroll office handles the reclassification; you don’t need to submit a new election.
The standard catch-up limit for employees 50 and older is $8,000 in 2026, meaning your total TSP contribution limit is $32,500. If you’re turning 60, 61, 62, or 63 this year, your catch-up limit is higher, $11,250 under a separate SECURE 2.0 provision, bringing your total to $35,750.
What It Means for Your Taxes This Year
Roth contributions are made with after-tax dollars. Unlike traditional TSP contributions, they don’t reduce your taxable income in the year you contribute.
If you’ve been directing catch-up contributions to traditional in prior years and counting on them to lower your adjusted gross income, that strategy no longer applies to the catch-up portion for 2026 if you’re above the 150K income threshold. For someone in the 24% bracket, losing the pre-tax treatment on $8,000 in catch-up contributions means roughly $1,920 more in federal income taxes this year. For someone in the 32% bracket, it’s closer to $2,560, before factoring in any state income tax impact.
The Silver Lining
The mandatory change isn’t purely bad news. Roth contributions, and everything they earn, come out tax-free in retirement, provided you meet the qualified withdrawal requirements. You’re paying more tax now, but buying yourself tax-free income later.
Whether that trade works in your favor depends on your expected tax rate in retirement. Federal retirees often have more taxable income than they anticipate. A FERS pension, Social Security, and traditional TSP distributions can push you into a higher bracket than you were in during your working years. If that’s your situation, the forced Roth catch-up may end up benefiting you.
It’s also worth considering the inheritance angle. Roth TSP balances pass to heirs tax-free, while traditional balances are taxable at every dollar distributed.
A Note on the $150,000 Threshold Going Forward
The threshold is not permanent at $150,000. It will be adjusted periodically for inflation, which means it may not apply to you every year. If your wages drop below the threshold in a future year, due to retirement, reduced hours, or a change in position, you would no longer be subject to the mandatory Roth rule for the following year, and your catch-up contributions could again go to traditional if you choose.
A Federal Retirement Consultant (FRC®) can help you evaluate your federal benefits and give you a clear snapshot of where you stand and what needs to be tweaked to meet your retirement goals.
