Say you’re 55, you earn $180,000 a year, and you’ve spent the last decade maxing out your 401(k), including the extra “catch-up” contribution, all in pre-tax dollars to shave down your tax bill. This year, the IRS won’t let you do that anymore. If your wages topped $150,000 last year, every dollar of your catch-up contribution now has to go in as Roth, after tax, whether that’s what you’d have chosen or not.

This is one of the quieter provisions of the SECURE 2.0 Act, and it finally took effect in 2026 after two years of delays. A lot of high earners are only finding out about it when their first paycheck of the year looks different. Here’s exactly what changed, who it hits, and the real math on what it costs you now versus what it saves you later.

What Actually Changed in 2026

For years, anyone 50 or older could add extra “catch-up” money on top of the regular 401(k) contribution limit, and choose whether that catch-up went in pre-tax (traditional) or after-tax (Roth). Most people picked pre-tax, since it lowers your taxable income right now.

Starting in 2026, that choice disappears for higher earners. If you made more than $150,000 in FICA wages from your employer last year, every catch-up dollar you contribute this year must be Roth. The threshold is indexed for inflation, so it started at $145,000 and has already climbed to $150,000. It’s measured by employer, using the wages reported on your W-2 from that specific company the previous year, not your household income and not wages from a different employer if you switched jobs.

The 2026 numbers, for reference: the regular 401(k) deferral limit is $24,500, the standard catch-up for anyone 50 and up is $8,000, and the enhanced “super” catch-up for people specifically 60 to 63 is $11,250. The mandatory Roth rule applies to all of it, however much catch-up you’re contributing.

Who This Rule Actually Applies To

You’re affected if all of the following are true:

• You’re age 50 or older this year (any catch-up-eligible age)
• Your prior-year FICA wages from your current employer exceeded $150,000
• You’re contributing to a 401(k) or 403(b) plan and putting in enough to reach the catch-up portion
• Your plan offers a Roth deferral option (more on what happens if it doesn’t, below)

A few wrinkles worth knowing. Employer matching contributions stay pre-tax no matter what, this rule only touches your own catch-up dollars. And because it’s based on last year’s wages at that specific employer, someone with variable commission income, or someone who just changed jobs, could be over the threshold one year and under it the next.

The Real Math: What This Costs You Right Now

Let’s use Sarah, 55, earning $180,000, who’s been maxing out her 401(k) at $32,500 a year ($24,500 regular plus $8,000 catch-up). In past years, that full $8,000 catch-up was pre-tax, so it reduced her taxable income dollar for dollar. In the 24% federal bracket, that saved her about $1,920 a year in taxes.

In 2026, her $8,000 catch-up has to be Roth. She’s still contributing the same amount, but it no longer reduces her taxable income, so her withholding goes up and she’ll owe roughly that same $1,920 more in tax this year than she would have under the old rules. That’s real money out of this year’s budget, not a paperwork change.

Here’s the part that balances it out. If Sarah keeps contributing $8,000 a year to Roth catch-up for the next 10 years and it grows at an average 7% annual return, that stream grows to about $110,500. Because it’s Roth, every dollar of that, contributions and growth, comes out completely tax-free in retirement. If that same $110,500 had built up in a traditional account instead and got taxed at 22% on withdrawal, she’d keep about $86,200. That’s a difference of roughly $24,300 in her pocket, just from the tax treatment at the back end.

So the honest answer is: it costs more now, and it can pay off later, but only if your tax bracket in retirement ends up close to or higher than your bracket today. If you’re confident you’ll be in a much lower bracket once you stop working, this mandatory switch is genuinely a worse deal for you than the old pre-tax option was. You don’t get a say in it anymore either way.

The Bigger Trap: Plans Without a Roth Option

This is the detail that catches people off guard. If your employer’s plan doesn’t offer a Roth deferral option at all, the rule doesn’t just skip you and let you keep contributing pre-tax. Instead, if you’re over the wage threshold, you lose the ability to make any catch-up contribution whatsoever until your plan adds a Roth feature.

Most large employers added Roth options well ahead of 2026 specifically to avoid this, but smaller plans and some nonprofit 403(b) plans are still catching up. If you’re a high earner over 50 and you’re not sure whether your plan offers Roth deferrals, that’s worth a two-minute email to HR or your plan administrator this week, before you find out the hard way that your catch-up contributions silently stopped.

What to Do About It Now

You can’t opt out of this rule if you’re over the threshold, but you can plan around it:

• Check your last few pay stubs to confirm your catch-up contributions are actually being routed to Roth, not accidentally rejected
• Adjust your withholding or estimated payments so the smaller pre-tax deduction doesn’t surprise you at tax time
• Confirm with HR whether your plan offers a Roth deferral option, especially if you work for a smaller employer
• Rethink your overall pre-tax versus Roth mix elsewhere, since your regular $24,500 deferral can still be pre-tax even though your catch-up can’t

Because this rule permanently shifts money from pre-tax into tax-free growth, it’s worth modeling how it actually plays out for your own numbers and timeline. Plug your numbers into our retirement calculator to see how your catch-up contributions, Roth or traditional, grow between now and the age you plan to retire.

Frequently Asked Questions

Does this rule apply to IRAs too?

No. The mandatory Roth catch-up rule only applies to employer-sponsored plans like 401(k)s and 403(b)s. Traditional and Roth IRA catch-up contributions still work exactly as they did before, with the same $150,000 threshold nowhere in the picture.

What if I earned over $150,000 but I’m under 50?

This rule only affects catch-up contributions, which are only available starting the year you turn 50. If you’re under 50, your wage level has no effect on how your 401(k) contributions are taxed.

Can I still choose pre-tax for my regular contribution limit?

Yes. The mandatory Roth requirement only touches the catch-up portion above the standard $24,500 limit. Your regular contributions can still be pre-tax, Roth, or a mix, exactly as before.