Millions of older workers counted on pre-tax 401(k) catch-up contributions to shave thousands off their annual tax bills during their highest-earning years. That familiar strategy no longer works for a significant portion of the workforce, and many savers missed the shift when it took effect in January.

Catch-up contributions are the vehicle that lets workers over 50 push past the standard deferral limit and fully maximize their 401(k) savings each year, according to the IRS. 

A key provision of the SECURE 2.0 Act now requires higher-income participants to direct those extra dollars into after-tax Roth 401(k) accounts.

The change eliminates the upfront deduction that made aggressive 401(k) deferrals appealing during peak earning years, right when the tax shelter matters most. 

Data from Vanguard’s How America Saves 2026 report, which tracks roughly 5 million plan participants, shows broader contribution patterns evolving alongside this mandate.

Also Read: Suze Orman flashes a 401(k) warning on saving for retirement

SECURE 2.0’s Roth catch-up mandate and the new 401(k) contribution limits

Section 603 of the SECURE 2.0 Act targets workers aged 50 and older whose 2025 Federal Insurance Contributions Act (FICA) wages topped $150,000. That dollar threshold, raised from $145,000 in the prior year, is adjusted annually for inflation under the schedule outlined in IRS Notice 2025-67.

Workers who exceed that wage floor can no longer route their catch-up dollars into a traditional pre-tax 401(k) to shrink their current-year tax bill. The 2026 deferral limit is $24,500, up from $23,500, and the catch-up cap for those 50 and older increased to $8,000, the IRS notice noted.

Workers between ages 60 and 63 can still access a higher catch-up of $11,250, unchanged from 2025, under the SECURE 2.0 framework. Only the catch-up portion triggers the Roth requirement, while the base $24,500 deferral can remain pre-tax for those who prefer it, the IRS reported.

Plans without a Roth 401(k) option must block affected participants from making catch-up contributions until the sponsor adds one, the Federal Register specified.

What Vanguard’s 2025 data shows about 401(k) catch-up participation

Vanguard’s How America Saves 2026 report, offers the broadest snapshot of workplace retirement behavior. The average participant deferral rate held steady at 7.6% of pay across the firm’s recordkeeping base, while the median landed at 6.6%.

Workers aged 55 and older deferred nearly twice as much of their pay as the youngest participants in the survey. Age served as the primary determinant of higher contribution rates across all plan types tracked in the survey, the data revealed.

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Only 45% of participants boosted their deferral rates in 2025, through individual decisions or automatic escalation features in their plans. 

Average total contribution rates, combining employee and employer contributions, reached 12.1%, up nearly two percentage points over the past decade, Vanguard reported.

Average account balances hit a record $167,970 at year-end 2025, up 13% from a year earlier, driven by market gains and broader participation, the data indicated.

Vanguard’s 2025 data reveals how age, contribution habits, and employer matches shape 401(k) savings, with average account balances reaching a record $167,970.

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Vanguard’s retirement consulting team sees the Roth mandate as an education opportunity

Only 16% of eligible participants used catch-up contributions in 2025, Vanguard found, meaning most older workers were not maximizing the pre-tax benefit the mandate now restricts.

Roth 401(k) plans have expanded since the account type launched in 2006, but worker-level adoption has consistently lagged behind plan-level availability. 

About 98% of Vanguard plans offered a Roth option at year-end 2025, up from 86% at year-end 2024, yet only 18% of workers used the feature when it was available, the Vanguard report detailed.

David Stinnett, Principal of Strategic Retirement Consulting & Solutions at Vanguard, told PlanSponsor the mandate will change how participants think about retirement tax planning.

<strong>It’s a good opportunity to educate people on the benefits of Roth and how it’s different, and the concept of tax diversification,</strong>

Vanguard’s December 2025 commentary on Roth contributions frames Roth savings as a way to achieve tax diversification alongside pre-tax 401(k) and traditional IRA balances, with the added benefit of locking in current tax rates against future increases. 

For high earners caught by the 2026 catch-up mandate, that after-tax exposure now builds by default.

How affected workers can protect their 401(k) catch-up contributions in 2026

Catch-up room lost during any period the plan lacks a Roth 401(k) option cannot be recovered later in the same tax year, under the final regulations.

The Roth catch-up requirement took effect January 1, 2026, but the final regulations issued in September 2025 don’t formally apply until January 1, 2027, for most plans. A good-faith interpretation standard covers plans during 2026 as payroll systems adjust, the IRS confirmed.

Hayden Adams, Director of Tax and Financial Planning at the Schwab Center for Financial Research, pointed affected savers toward funding a Roth IRA if modified adjusted gross income stays under the 2026 thresholds, or maxing out a health savings account tied to a high-deductible health plan.

“Adding such funds to your portfolio gives you greater tax flexibility,” Adams said.

Related: Vanguard spotlights Roth IRA trap hiding in your income