A 67-Year-Old With $2 Million in a 401(k) Discovers RMDs Will Trigger a $400,000 Tax Bill

The retiree who built a $2 million traditional 401(k) by age 67 did everything right: maxed contributions for decades, captured the employer match, and held steady through every market selloff. With $25,000 in Social Security already claimed and no Roth assets to speak of, the obvious next step seems to be letting the balance keep compounding until required minimum distributions kick in at 73. That single decision, left unchallenged, quietly hands the IRS a six-figure bill the retiree never agreed to pay.

What $2 Million Becomes by Age 73

Compound $2 million at 6% for six years and the balance reaches roughly $2.84 million. That growth looks like a win, but the IRS has been waiting for it. Under SECURE 2.0, the first RMD arrives at age 73 for anyone born between 1951 and 1959. Per IRS Publication 590-B, the Uniform Lifetime Table divisor at age 73 is 26.5, meaning the prior year-end account balance is divided by that figure to produce the mandatory withdrawal. Those divisors have been in effect since 2022 under Treasury Decision T.D. 9930, and the IRS has not announced a revision for 2026.

The arithmetic is uncomfortable: $2.84 million divided by 26.5 equals roughly $107,170. That is the forced withdrawal in year one, taxed as ordinary income whether the retiree spends a cent of it or not. A timing trap compounds the problem further. The IRS allows a first-time RMD to be delayed until April 1 of the following year, but taking that delay means two RMDs land in the same calendar year. Stacking two distributions in one filing can push the retiree into a higher bracket or over the Medicare surcharge threshold in a single jump.

How the RMD Stacks With Social Security

The RMD does not arrive alone. It lands on top of Social Security. With $25,000 in benefits, the combined income pushes 85% of those benefits, or $21,250, into taxable territory, bringing gross taxable income to $128,420. Subtract the $18,150 standard deduction available to a single filer age 65 or older in 2026 (the $16,100 base plus the $2,050 age add-on under IRC Section 63(f)), and taxable income lands near $110,270, squarely inside the 24% bracket.

The One Big Beautiful Bill Act introduced a new $6,000 senior deduction for tax years 2025 through 2028, available to filers 65 and older whether they itemize or take the standard deduction. For single filers, it phases out at 6 cents for every dollar of MAGI above $75,000 and disappears entirely at $175,000. A retiree projecting $128,000 in income sees only a partial benefit of roughly $2,820, because the phase-out trims the full deduction by about $3,180. That partial offset is real money, but it does not fundamentally change the bracket picture.

Federal tax in year one alone runs $19,000 to $21,000 before factoring in IRMAA. In 2026, the first Medicare surcharge threshold sits at $109,000 MAGI for single filers. The standard Part B premium is $202.90 per month, a meaningful jump from $185.00 in 2025. Once income clears that $109,000 threshold, total Part B costs climb from $284.10 to $689.90 per month depending on income tier, and Part D surcharges add $14.50 to $91.00 per month on top of plan premiums. Because IRMAA uses a two-year lookback tied to the prior-prior-year tax return, a 73-year-old’s first large RMD raises Medicare premiums at 75, not immediately. The surcharge also operates as a cliff: crossing a threshold by even one dollar triggers the full additional cost for the entire year.

Why It Compounds Every Year

The divisor shrinks as the retiree ages. At 75 it falls to 24.6, at 80 to 20.2, at 85 to 16.0, and at 90 to 12.2. A smaller divisor applied against a balance still growing at market rates means the forced withdrawal expands in both nominal and real terms each year. Cumulative RMD-driven federal tax over a 20-year retirement can exceed $400,000, and that figure arrives before state tax, before IRMAA, and before the widow’s penalty that hits a surviving spouse suddenly filing single on the same income stack. Roughly 12 million Americans aged 73 and older face this situation annually, and most encounter it without a plan in place.

Persistent inflation deepens the problem. Nominal RMDs rise alongside a growing account balance, but tax bracket thresholds adjust more slowly than a portfolio compounding at market rates. That mismatch quietly pushes more income into higher brackets year after year, even when actual spending stays flat. The retiree who does nothing is not simply deferring a decision; the inaction is itself a choice, and an expensive one.

Four Levers That Actually Move the Number

1. Bracket-filling Roth conversions between 67 and 73. Converting enough each year to fill the 22% or 24% bracket without spilling into the next one gives six years of disciplined action that can shrink the traditional balance by hundreds of thousands of dollars, permanently lowering every future RMD. With the 10-year Treasury near 4%, conversions also lock in today’s rates against future bracket creep.
2. Qualified Charitable Distributions after 70½. A QCD sends IRA dollars directly to a qualified charity, counts toward the RMD, and never enters AGI. The 2026 QCD limit is $111,000 per person, up from $108,000 in 2025, per IRS Notice 2025-67. One important caveat: QCDs apply only to traditional IRAs, not directly to a 401(k). A retiree with funds still sitting in a 401(k) who wants to use this strategy should first roll the balance into a traditional IRA. The OBBBA also reshapes the math for itemized giving: non-itemizers can deduct up to $1,000 in cash charitable gifts, but that cap is modest, while itemizers face a new 0.5% AGI floor on donations and a cap limiting deduction value to 35 cents on the dollar. A QCD sidesteps both restrictions entirely because it is an income exclusion rather than a deduction, and the AGI reduction feeds back into lower IRMAA exposure two years forward. For charitably inclined retirees, it remains the cleanest RMD offset the tax code offers.
3. A Qualified Longevity Annuity Contract. A QLAC lets a retiree carve up to $210,000 of a 401(k) or IRA balance out of the RMD calculation entirely, deferring income to as late as age 85. SECURE 2.0 simplified the rules by eliminating the old 25% of account balance limit and replacing it with a flat dollar cap that adjusts for inflation each year per IRS Notice 2025-67. The practical result is a product that shrinks the divisor problem while hedging longevity risk at the same time.
4. Spousal sequencing for married couples. The widow’s penalty converts a joint return into a single return overnight, often on an identical income level. Coordinating which spouse converts, which claims Social Security first, and which account passes to the survivor can flatten the post-death tax cliff considerably. A withdrawal strategy that looks manageable on a joint return can become punishing once the surviving spouse files single on the same income stack.

What to Do This Quarter

Start with your own version of the math. Take the current 401(k) balance, compound it at an expected return to age 73, divide by 26.5, and stack the result on top of Social Security and any pension income. If the projected total clears the first IRMAA threshold of $109,000 for single filers, the Medicare surcharge alone justifies engaging a fee-only CPA or financial planner who models multi-year conversions. The IRS Uniform Lifetime Table in Publication 590-B shows the divisor at every age from 73 to 90, and reviewing it early is worth the hour it takes. Keep in mind that those born in 1960 or later face a starting RMD age of 75 rather than 73, which shifts the planning window but does not eliminate the underlying problem. The retiree who waits until 72 to start planning has already surrendered most of the available room to maneuver.

Editor’s note: This pass added context on the Part B premium increase from $185.00 in 2025 to $202.90 in 2026, confirmed the 2026 QLAC limit of $210,000 per person per IRS Notice 2025-67, and verified the 2026 QCD limit of $111,000 per person (up from $108,000 in 2025). The 2026 standard deduction of $18,150 for single filers 65 and older and the IRMAA first-tier threshold of $109,000 MAGI for single filers were also confirmed against current IRS and CMS guidance.

Contact [email protected] for any questions or corrections.