Most retirement advice points one direction: contribute as much as possible, as early as possible, every year without exception. But a closer look at what happens to pre-tax dollars in retirement reveals a trap hiding inside decades of conventional wisdom.
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Take a married couple, both 63, with about $1.4 million split across two 401(k)s. One spouse earns well above $150,000. For a decade they maxed both accounts every January. This year they cut contributions to the level that gets the employer match, and the projection for their after-tax retirement income improved.
That result runs against every savings rule of thumb. It holds up because of what happens to pre-tax dollars when they come back out.
What Maxing Out Buys at 63
The contribution ceiling is higher than ever. The standard 2026 limit is $24,500, and workers aged 60 to 63 get a super catch-up of up to $11,250, for a total of $35,750 each. At 64, the enhanced catch-up goes away.
A new issue arrived with it. Under SECURE 2.0, workers 50 and older who earned more than $150,000 in prior-year wages must now make catch-ups as Roth contributions.
Tom O’Saben of the National Association of Tax Professionals estimated that a worker in the 24% bracket loses about $2,700 in federal tax savings on a maximum super catch-up. So the high earner’s catch-up is already Roth money. The real question for this couple was whether the base contribution should keep going in pre-tax.
Pre-Tax Savings Return as a Tax Cascade
A pre-tax contributions saves tax at today’s rate and gets taxed again at tomorrow’s. In 2026, joint filers will see the 24% bracket start above $211,400 of taxable income, and the 22% bracket start above $100,800. Most retirees expect to drop a bracket, and on paper they usually do.
Paper leaves out two surcharges. Once provisional income for a married couple passes $44,000, up to 85% of their benefits become taxable, so every extra 401(k) dollar draws benefit dollars into the tax base with it. Higher income also sets off Medicare IRMAA surcharges of roughly $70 to $400+ per month per person.
Combined, a retiree nominally in the 22% bracket can face an effective marginal rate near 40%. Postponing tax at 24% to pay it later at 40% is a losing trade.
Balance size drives the damage. Someone turning 63 in 2026 was born in 1963, so required minimum distributions begin at age 75. Every additional year of pre-tax contributions compounds until then, and the forced withdrawals grow right along with it.
Where the Redirected Money Went
This couple split the freed-up cash two ways. The first slice became Roth dollars. As Fidelity’s Angela Capek told the New York Times, Roth 401(k) balances have carried no required withdrawals since 2024. Qualified Roth withdrawals also stay out of provisional income, so they never trip the Social Security or IRMAA wires.
A taxable bridge fund got the second slice. Treasury yields are elevated, with the 10-year near 5.1%, so a Treasury ladder can cover spending from when paychecks end until age 70 while Social Security waits.
Each year you wait beyond full retirement age at 67 adds 8% to the benefit permanently. That larger check is also inflation-protected, and the 2027 cost-of-living adjustment is tracking toward 3.3%.
Bank CDs make a weak substitute. The national average 12-month CD pays just 1.73%, and that interest counts toward provisional income, too. Treasury interest at least escapes state income tax.
Put the pieces together and the couple gets a bigger lifetime Social Security check, smaller RMDs at 75, and a Roth bucket for high-spending years. Contributing less to the pre-tax side produces more spendable income later.
Three Moves Before Open Enrollment
- Pull Box 3 of your 2025 W-2, which shows wages subject to Social Security tax. If that figure exceeds $150,000, your catch-up already goes Roth. Use that as the prompt to decide whether contributions above your employer match belong pre-tax at all.
- Project your traditional balance to your RMD age, then divide it by the factor in the IRS Uniform Lifetime Table. If that first distribution plus both Social Security checks lands your household in the 22% bracket or higher, trim pre-tax contributions to the match and move the rest to Roth and a Treasury bridge fund.
- Respect the two-year Medicare lookback. Income you report at 63 sets your premiums at 65, so schedule any Roth conversions for the gap years after the paychecks stop and before Social Security starts. If projected income in those years crosses the initial IRMAA tier, the tax planning alone warrants paying a fee-only advisor.
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