64-Year-Old With $1.1 Million 401(k) Drains It Early to Lock in 8% Guaranteed Social Security Bump

Linda is 64, retired last spring, and sitting on a $1.1 million traditional 401(k). Her Social Security statement projects a benefit of $5,181 per month at age 70. Instead of letting the 401(k) compound and claiming Social Security now, she is doing the opposite: pulling roughly $85,000 a year from the 401(k) while deferring Social Security for six more years. On paper it looks reckless. On a spreadsheet, it is one of the most tax-efficient moves a retiree in her bracket can make.

The 8% Guaranteed Return Nobody Else Can Match

Every year Linda delays claiming past her full retirement age, her benefit grows by 8%. That is a government-backed, inflation-linked increase on top of the annual cost-of-living adjustment. The 2026 COLA came in at 2.8%, and because headline inflation has been running well below that figure, the real purchasing power of a delayed benefit is compounding in Linda’s favor. Forward estimates for the 2027 COLA are currently tracking around 3.8%, suggesting the inflation-protection angle of a larger delayed benefit could matter even more in the near term.

Compare that 8% credit to what her portfolio can earn safely. The 10-year Treasury is yielding around 4.7%, and the Federal Reserve held its target range at 3.5% to 3.75% at its July 2026 meeting, with markets pricing in a possible hike later in the year. Nothing on the risk-free side of her account statement pays 8% guaranteed. Delaying Social Security is functionally a bond ladder no broker sells.

The Bridge Math on $1.1 Million

Linda needs income now. The Bureau of Labor Statistics puts average annual household expenditures at $78,535 for 2024, and her budget is close to that. Six years of $85,000 withdrawals gross out to roughly $510,000, less than half the balance. If the remaining portfolio earns a blended 5% to 6% while she draws down, she will still have several hundred thousand dollars left when the $5,181 monthly check finally starts.

The tax angle is the piece most retirees miss. From 64 to 69, Linda has almost no other taxable income. Her 401(k) withdrawals fill up the standard deduction and the lower brackets before she ever touches the 22% rate. In 2026, a single filer’s 12% bracket ends at $50,400 of taxable income. Add the $16,100 standard deduction and Linda can bring in roughly $66,500 of gross traditional 401(k) income while staying entirely inside the 12% federal bracket. Stacking withdrawals on top of Social Security later would push those same dollars into a higher bracket, make 85% of her Social Security benefits taxable, and risk triggering her first IRMAA Medicare surcharge, which in 2026 kicks in at $109,000 of income for single filers.

The Roth Conversion Window Hiding Inside the Plan

The same low-income window that makes cheap withdrawals possible also opens a Roth conversion door. Linda can withdraw what she needs to live on, then convert an additional $30,000 to $40,000 into a Roth IRA each year while still staying under the 22% bracket. Every dollar converted before 70 is a dollar that will never appear in a future required minimum distribution calculation and never inflate the taxable portion of her benefit.

The window has grown more valuable in 2026. The One Big Beautiful Bill Act created a new $6,000 above-the-line bonus deduction for taxpayers age 65 and older, stacking on top of both the $16,100 standard deduction and the existing $2,050 age-65 additional deduction. The bonus is temporary, available for tax years 2025 through 2028, and it phases out above $75,000 of modified adjusted gross income for single filers, disappearing entirely at $175,000. For Linda, whose withdrawals and conversions will likely keep her well under that phase-out floor, the extra deduction means more room to withdraw or convert at low rates before hitting the 22% bracket. Every dollar of additional headroom is a dollar she can either spend tax-cheaply or shelter in a Roth permanently.

This is the core piece that quietly rescues the plan. A fuller walkthrough of the timing lives inside The Social Security Decision. By the time RMDs begin at 75, her traditional balance is smaller, her Roth is meaningful, and her Social Security check is 24% larger than it would have been had she claimed at her full retirement age of 67.

Readers can model their own version with different balances and claiming ages:

The break-even point on delayed claiming typically lands in the early 80s. Anyone with reasonable health and family longevity clears it without difficulty.

What to Do Before Year-End

1. Pull your personalized Social Security statement. Confirm the exact benefit at 62, at full retirement age, and at 70. The 8% delayed credit only accrues between full retirement age and 70, not from 62 onward.
2. Map your withdrawals against the tax brackets. The 2026 12% bracket for single filers ends at $50,400 of taxable income. Add the $16,100 standard deduction plus the $2,050 age-65 additional deduction. If you are 65 or older and your MAGI is below $75,000, stack the new $6,000 OBBBA senior bonus deduction on top to find your gross income ceiling. Withdraw enough to fill that space, then decide whether a partial Roth conversion into the 22% bracket still beats the future tax cost of leaving the money in traditional. Keep in mind that the $6,000 senior bonus phases out above $75,000 MAGI and sunsets after the 2028 tax year.
3. Watch the two-year IRMAA lookback. Income in the calendar year you turn 63 sets your Medicare Part B and D premiums at 65. The 2026 first-tier surcharge threshold for single filers is $109,000. If a large withdrawal or conversion is coming, model the premium surcharge before you sign the paperwork.

Editor’s note: This update adds the OBBBA senior bonus deduction phase-out threshold ($75,000 MAGI for single filers, sunsetting after 2028) and the $2,050 age-65 additional standard deduction figure for 2026, notes that 2027 COLA estimates are currently tracking around 3.8%, and reflects the Federal Reserve’s confirmed July 2026 decision to hold its target rate at 3.5% to 3.75% alongside market pricing for a possible hike later this year.

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