The SECURE 2.0 Act's most consequential change for older savers takes effect this year. Beginning January 1, 2026, participants age 50 and older who earned more than $150,000 in prior-year FICA wages from the employer sponsoring the plan must make their 401(k) catch-up contributions on an after-tax Roth basis rather than pre-tax. The IRS raised the threshold from the original $145,000 to $150,000 in November 2025, and issued final regulations that give plan sponsors a good-faith compliance window through the end of 2026.
For workers who are used to reducing current taxable income by maxing out pre-tax deferrals, the mandate is a real change. It arrives at the same time as the broader 2026 contribution increases, which raise the ordinary 401(k) deferral limit to $24,500, the standard age-50 catch-up to $8,000, and the SECURE 2.0 "super catch-up" for ages 60–63 to $11,250. The IRA limit rises to $7,500, with a $1,100 catch-up.
Who Is Actually Affected
The $150,000 test is based on the prior year's W-2 wages from the plan sponsor, not household income or self-employment earnings. A worker who earned $155,000 in 2025 must Roth-source their catch-up contributions in 2026, even if they change jobs mid-year. A worker who earned $140,000 in 2025 can still make pre-tax catch-ups in 2026 regardless of a 2026 raise. Wages from a different employer do not count toward the test at the current plan.
Two other details matter. First, if the employer's plan does not offer a Roth 401(k) feature, affected participants cannot make catch-up contributions at all until the plan is amended. Second, the rule is permanent, and the $150,000 threshold is indexed for future cost-of-living adjustments.
The Tax Trade-Off Is Not Automatic
Roth catch-up contributions are made with after-tax dollars and grow tax-free. Pre-tax catch-ups reduce current taxable income but are taxed at ordinary rates on withdrawal. For a household in the 32% or 35% federal bracket during peak earning years, losing the pre-tax deduction on an $8,000 catch-up contribution is a real cash-flow cost — roughly $2,600 to $2,800 in additional current-year tax.
That cost is not necessarily a bad trade. Workers who expect to retire into a similar or higher tax bracket, who already hold large pre-tax balances subject to future required minimum distributions, or who value tax diversification often come out ahead over a full retirement horizon. The Roth balance also compounds free of future rate risk, which matters if statutory rates rise from current post-TCJA levels.
Practical Steps Before Year-End Payroll Starts
- Confirm the plan offers a Roth feature. Affected employees should verify with HR that Roth 401(k) contributions are permitted and that payroll systems have been updated for the new sourcing rule.
- Recalibrate the household tax plan. The lost deduction can push some households into higher effective marginal territory. Coordinating with a tax advisor on withholding, estimated payments, and any planned Roth conversions is worthwhile before Q1.
- Use the full 2026 architecture. The Roth mandate applies only to the catch-up portion. The base $24,500 deferral can still be made pre-tax at the participant's election. Households can also use the $7,500 IRA limit and, where cash flow allows, direct additional after-tax savings toward a Roth IRA or backdoor Roth.
- Do not lose the super catch-up. Workers ages 60–63 retain access to the $11,250 super catch-up in 2026, but for high earners it must also be made as Roth. That is the single largest tax-free contribution window most savers will ever have — worth funding fully if cash flow permits.
The Roth catch-up mandate does not shrink how much older workers can save; it changes the tax character of the savings. Treating the change as a planning event rather than a payroll footnote is the difference between a smooth 2026 and an April 2027 surprise.
Sources: Internal Revenue Service, Fidelity, Charles Schwab, Manulife John Hancock Retirement, Quarles Law Firm