A 65-year-old single woman walks into retirement with $1.8 million in a traditional 401(k), $250,000 in a taxable brokerage, and $100,000 in cash. She wants to spend $80,000 a year. The conventional wisdom says to file at full retirement age 67 and let the 401(k) keep compounding. A smarter sequence flips that logic entirely: draw down the 401(k) and brokerage from ages 65 to 70, and let the Social Security check grow to its maximum before touching it.
Why the bridge years are worth more than the deferral
Her benefit at full retirement age would be $36,000 a year. Waiting until 70 turns that into $44,640 a year, courtesy of the 8% delayed retirement credit per year past FRA. Those credits accumulate at two-thirds of 1% per month and stop accruing entirely at 70, so filing even one month late past that birthday means forfeited income with no path to recovery. Run the higher check out to age 90 and the extra income totals $172,800 in nominal dollars, before any cost-of-living adjustment compounds on the larger base. With the consumer price index posting a 4.2% annual rate in May 2026, its highest reading since April 2023, locking in a bigger inflation-adjusted base matters more urgently than it did just a few years ago.
The five-year drawdown math
Five years of $80,000 spending equals $400,000. Splitting withdrawals roughly evenly between the 401(k) and the brokerage keeps her inside the lowest two federal brackets throughout the bridge period. In 2026, a single filer aged 65 or older claims a base standard deduction of $16,100 plus an additional $2,050 age deduction, for a combined $18,150 shielded from tax before a dollar of 401(k) income is counted. Layered on top of that, the One Big Beautiful Bill Act created a separate temporary $6,000 senior bonus deduction for single filers aged 65 and older with modified adjusted gross income below $75,000, available for tax years 2025 through 2028. That additional shelter can push effective taxable income well below the 12% bracket ceiling.
Taking $40,000 from the 401(k) and subtracting the $18,150 combined deduction leaves roughly $21,850 of taxable income. That sits comfortably inside the 12% bracket, which runs to $48,475 for single filers in 2026, and produces roughly $2,600 in federal tax per year, or about $13,000 across the five-year bridge.
The brokerage half is even cheaper to access. Long-term capital gains stacked on top of that modest ordinary income largely fall inside the 0% capital gains rate, which applies to taxable income up to $49,450 for single filers in 2026. Any unrealized losses in the portfolio can be harvested to offset future gains, compressing the tax bill further still.
The RMD and Social Security tax cascade she avoids
Draining roughly $200,000 from the 401(k) during the gap years reduces her year-one required minimum distribution at age 73 by about $7,800. That is meaningful on its own, but the bigger prize is the provisional-income math. Once Social Security starts, single filers see up to 50% of benefits become taxable above $25,000 of provisional income, and up to 85% above $34,000. Those thresholds have not been indexed for inflation since 1984, which means more retirees collide with them every year.
A larger Social Security check at 70 displaces the 401(k) withdrawals that would otherwise push her over those cliffs. A retiree in the 22% bracket who simultaneously triggers 85% Social Security taxation and an IRMAA Medicare surcharge can face an effective marginal rate near 40% on the next dollar pulled from the 401(k). The bridge strategy is built to keep her well clear of that trap.
The rate environment provides another tailwind. The Federal Reserve held its benchmark federal funds rate at 3.5% to 3.75% through its June 17, 2026 meeting, the fourth consecutive hold, while markets heading into the July 28 to 29 FOMC meeting priced roughly a 25% chance of a 25-basis-point hike later in 2026 if inflation proves persistent. Cash and short-duration bonds inside the 401(k) still generate a real return at these levels, so the bridge period does not quietly erode purchasing power while it works.
What to do in the next 30 days
- Map the bracket fill. Pull only enough from the 401(k) each year to bring taxable income to the top of the 12% bracket. With the 2026 single 12% bracket ending at $48,475, that leaves room for small bracket-filling Roth conversions inside the same window, shrinking future RMDs further.
- Run the brokerage first on appreciated lots with offsetting losers. Harvest losses while drawing it down so that capital gains stay inside the 0% rate and never collide with the eventual Social Security check.
- File for Social Security the month you turn 70. Delayed retirement credits stop accruing at 70. Waiting even a single extra month past that birthday is pure forfeited income.
The arithmetic favors the reverse sequence. Spend the tax-deferred dollars while the standard deduction and age-related deductions are absorbing them, and let the inflation-protected government annuity grow to its largest possible base before the first check ever arrives.
Editor’s note: This pass corrected the 2026 single-filer 12% bracket ceiling from $50,400 to $48,475, the figure confirmed by IRS Rev. Proc. 2025-28. It also updated the Federal Reserve rate discussion to reflect the July 28 to 29, 2026 FOMC meeting context, including market pricing of a roughly 25% probability of a 25-basis-point hike later this year.
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