The Three-Account Withdrawal Order That Saved a $2.4 Million Retiree $187,000 in Lifetime Taxes

A 64-year-old couple holds $1.5 million in a traditional 401(k), $500,000 in a Roth IRA with the five-year clock satisfied, and $400,000 in a taxable brokerage account with a $250,000 cost basis. They spend $130,000 a year, plan to claim Social Security at 70 for a combined $58,000 benefit, and have nine years before required minimum distributions begin. The order in which they draw from these three buckets between now and age 73 is worth roughly $187,000 in lifetime federal tax savings. That single decision, made once at the kitchen table, determines the entire outcome.

Why the conventional rule of thumb fails

The textbook sequence (brokerage first, 401(k) next, Roth last) protects tax-free growth and looks clean on a spreadsheet. Run it across 30 years and it produces about $462,000 in lifetime federal tax. The reason is mechanical: the 401(k) sits untouched and compounds to roughly $3.4 million by age 73, at which point the first RMD lands at around $130,000. Stacked on top of Social Security, that withdrawal pushes provisional income high enough to make 85% of benefits taxable and lands the couple in IRMAA Tier 3 or higher for the rest of their lives, where Medicare Part B and D surcharges run several thousand dollars per person per year.

Spending the Roth first (Sequence B) trims lifetime tax to about $385,000 because the Roth reserve that would have capped IRMAA exposure later is already gone when the RMD wall arrives. That is an improvement, but the structural problem remains: an oversized pre-tax account waiting at age 73.

The proportional bracket-fill, year by year

The strategy that wins treats all three accounts as one portfolio held in three different tax wrappers, then drains the 401(k) every year to the top of the 12% bracket, whether the couple needs the cash or not. Under 2026 rules, the 12% MFJ bracket extends to $100,800 in taxable income and the standard deduction is $32,200, with an additional $1,650 per qualifying spouse age 65 or older on top. That creates room for roughly $66,950 of 401(k) withdrawals taxed inside the 12% bracket before a single dollar tips into 22%.

One additional piece of 2026 planning deserves attention. The One Big Beautiful Bill Act introduced a temporary senior bonus deduction of $6,000 per qualifying individual age 65 or older ($12,000 for a qualifying MFJ couple) for tax years 2025 through 2028. This deduction phases out above $150,000 of modified adjusted gross income for joint filers, so it may not be available in years when the couple pulls heavily from the 401(k). But in early retirement years, before full Social Security kicks in, the bonus deduction can expand the bracket-fill room further, making this window even more valuable.

The remaining $63,050 of annual spending comes from the other two buckets:

1. $33,000 from the brokerage. Most of that is return of basis. The embedded gain of roughly $12,000 fits inside the 0% long-term capital gains bracket, which extends to $98,900 of taxable income for MFJ couples in 2026. Zero federal tax on the gain.
2. $30,000 from the Roth. Tax-free, and critically, invisible to the Social Security taxation formula and the IRMAA income test.
3. $66,950 from the 401(k). Taxed in the 10% and 12% layers only, producing the bulk of an annual federal bill of around $8,000.

Run that pattern for nine years and the 401(k) arrives at age 73 small enough that RMDs stay inside the 12% bracket. Lifetime federal tax across 30 years drops to roughly $275,000.

The second-order benefits

Two structural features make this sequence more durable than the headline tax savings suggest. The brokerage account retains enough long-held positions to receive a step-up in basis at the first spouse’s death, erasing decades of embedded gains in a single event. The Roth is intentionally left intact as a reserve for the post-65 years, when an unplanned expense (a roof, a car, a long-term-care premium) would otherwise force a 401(k) withdrawal that breaches an IRMAA threshold. With the 10-year Treasury yielding approximately 4.7% and the Fed funds target range at 3.50% to 3.75%, even the cash sleeve inside the Roth earns a usable real return while it waits.

What to do this week

1. Project your 401(k) balance at age 73 using a conservative 6% return, then divide by 26.5 to estimate your first RMD. If that number lands above the top of the 12% bracket plus your standard deduction, you have a bracket-fill problem to solve this year.
2. Calculate the exact dollar amount that fills the 12% bracket for your filing status in 2026, subtract expected Social Security and pension income, and convert or withdraw the difference from the 401(k) before December 31.
3. Sell brokerage lots with embedded gains up to the 0% LTCG ceiling in the same year. The capacity expires every December and does not roll forward.

Editor’s note: This update corrected the 2026 zero-percent long-term capital gains threshold for married couples filing jointly from $96,700 (the 2025 figure) to $98,900, updated the 10-year Treasury yield reference to reflect the current level of approximately 4.7%, revised the Fed funds target to the full 3.50%-3.75% range confirmed at the July 2026 FOMC meeting, and added context on the One Big Beautiful Bill Act’s new $12,000 senior bonus deduction for qualifying couples age 65 and older.

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