Starting January 1, 2026, millions of high-earning workers face a mandatory change to how they make 401(k) catch-up contributions. Under the SECURE Act 2.0's Section 603, if you're age 50 or older and earned $150,000 or more in FICA wages from your employer in the prior year, every dollar of your catch-up contribution must go into a designated Roth account — not pre-tax. There is no opt-out.
This isn't a small technical detail. It affects roughly 8 million workers and changes the tax math that many people built their retirement strategy around.
What Is the Mandatory Roth Catch-Up Rule?
Standard 401(k) contributions have an annual limit ($24,500 for 2026). Workers age 50 and older can contribute an additional "catch-up" amount on top of that — $8,000 for most, or $11,250 for the special "super catch-up" window if you turn 60, 61, 62, or 63 by December 31.
Before 2026, you could direct these catch-up contributions to either your traditional (pre-tax) 401(k) or your Roth 401(k), depending on what your employer's plan offered and what made sense for your taxes.
Starting January 1, 2026, that choice is gone for high earners. If the employer sponsoring your retirement plan paid you $150,000 or more in FICA wages (W-2 Box 3) in 2025, your 2026 catch-up contributions must be Roth. The rule is in IRC § 414(v)(7)(C), finalized in IRS regulations in early 2026.
Who Is Affected — and Who Isn't
The rule applies to you if all three conditions are true:
- You are age 50 or older during 2026
- You earned $150,000 or more in FICA wages (W-2 Box 3) from the employer sponsoring your 401(k) in 2025
- Your employer's plan includes catch-up contributions
The $150,000 threshold is checked against W-2 Box 3 — Social Security wages — not your total gross compensation. This matters because pre-tax benefits like health insurance and FSA contributions reduce Box 3. Someone who grosses $160,000 but deducts $15,000 pre-tax has $145,000 in Box 3 and does not trigger the rule.
If you work for two employers, only the employer that sponsors the 401(k) you're making catch-up contributions to is counted. Your other employer's wages don't factor in.
The rule does not apply if:
- You earned less than $150,000 in FICA wages from the sponsoring employer in the prior year
- You are under age 50
- Your plan does not offer catch-up contributions at all
The Super Catch-Up and the Forced Roth Problem
Workers aged 60, 61, 62, or 63 qualify for the "super catch-up" — $11,250 in 2026 instead of the standard $8,000. This window is one of the best retirement savings opportunities in the tax code: a four-year period with meaningfully higher limits that reverts back to $8,000 the moment you turn 64.
For high earners in this age range, the forced Roth rule applies to the full $11,250. If you were expecting to get a $11,250 pre-tax deduction, you now pay full income taxes on that amount in 2026.
What Happens If Your Plan Doesn't Offer a Roth Option?
This is the rule's most severe consequence, and it affects thousands of workers at smaller companies.
If your employer's retirement plan does not include a designated Roth 401(k) account, high earners subject to the rule cannot make any catch-up contributions at all. The IRS position is clear: you can't use the pre-tax catch-up as a workaround. No Roth option = no catch-up.
That means losing up to $8,000 or $11,250 in annual savings capacity entirely. Contact your HR department now if you think this applies to you — most major recordkeepers (Fidelity, Vanguard, Schwab, Empower) can add Roth functionality to existing plans, but it takes time to implement.
What Does It Actually Cost You?
Switching from pre-tax to Roth catch-up doesn't increase the dollar amount you can contribute — you can still put in up to $8,000 (or $11,250). But you lose the upfront tax deduction.
In 2025, contributing $8,000 pre-tax reduced your federal taxable income by $8,000. At a 32% marginal rate, that saved $2,560 in federal taxes, plus whatever your state taxes. Now you pay that $2,560 (or more, depending on your state rate) this year.
The long-run story is more complex. Roth contributions grow tax-free, and qualified withdrawals in retirement are tax-free — meaning future earnings on the catch-up amount are never taxed. Whether forced Roth is better or worse than pre-tax over your lifetime depends on:
- Your current marginal tax rate
- Your expected tax rate in retirement
- Years remaining until you retire
If your tax rate is meaningfully lower in retirement — which is common for high earners who plan to withdraw slowly from large pre-tax accounts — forced Roth costs you money over the long run. If your retirement tax rate is similar or higher, forced Roth is neutral or even beneficial.
Use the calculator below to see your specific numbers:
→ Mandatory Roth Catch-Up Calculator 2026 — Enter your wages, age, marginal rates, and years to retirement to see your extra tax cost this year, your recommended W-4 adjustment, and the long-term break-even comparison.
Adjusting Your W-4 Withholding
If you've been making pre-tax catch-up contributions, your current W-4 withholding was set with that deduction in mind. Switching to Roth means your taxable income is $8,000–$11,250 higher than your employer's payroll system expects.
You will likely owe more federal and state taxes at year-end unless you adjust your W-4 to withhold additional amounts. The IRS Withholding Estimator can help, but the Mandatory Roth Catch-Up Calculator shows a specific dollar amount to add per paycheck based on your situation.
Key Dates and IRS Guidance
| Date | Event | |------|-------| | December 29, 2022 | SECURE Act 2.0 enacted; Section 603 added mandatory Roth catch-up rule | | August 25, 2023 | IRS Notice 2023-62: announced 2-year administrative transition period | | January 1, 2026 | Mandatory Roth catch-up rule takes effect (after the transition period) | | 2026 | IRS final regulations effective |
The IRS granted a two-year transition period through 2025 to give employers time to update their plan documents and payroll systems. That transition ended on January 1, 2026. Employers who have not updated their plans are now exposed to operational errors.
Frequently Asked Questions
Does the rule apply to 403(b) and 457(b) plans? Yes. The mandatory Roth catch-up rule applies to 401(k), 403(b), and governmental 457(b) plans. It does not apply to non-governmental 457(b) plans.
What if I have multiple jobs? Do wages from all employers count? No. Only FICA wages paid by the employer sponsoring the plan to which you're making catch-up contributions count toward the $150,000 threshold. Wages from a second employer do not factor in, even if they're on the same W-2 form.
Can I still make regular (non-catch-up) contributions pre-tax? Yes. The mandatory Roth rule applies only to catch-up contributions — the amount above the $24,500 base limit. Your regular contributions up to $24,500 can still go to pre-tax, Roth, or any combination.
What if I turn 64 during 2026? If you are 64 during 2026, you do not qualify for the super catch-up ($11,250). You revert to the standard catch-up ($8,000). If you earned over $150,000 in 2025, that $8,000 must still be Roth.
Is there a penalty for employers who don't implement this correctly? Yes. Plans that allow high earners to make pre-tax catch-up contributions after January 1, 2026 are making an impermissible contribution, which could jeopardize the plan's qualified status. Employers should audit their payroll systems now.