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 roughly 8%. That is a government-backed, inflation-linked bump on top of the annual cost-of-living adjustment. The 2026 COLA came in at 2.8%, and current headline inflation is running at just 1.6% year over year, so the real purchasing power of that delayed benefit is compounding.

Compare that 8% credit to what her portfolio can earn safely. The 10-year Treasury is yielding almost 5%, and the fed funds rate sits near 4%. 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, 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 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. That means her 401(k) withdrawals fill up the standard deduction and the lower brackets before she ever touches the 22% rate. A single filer can pull roughly $63,000 in traditional 401(k) money and stay inside the 12% federal bracket. Stacking withdrawals on top of Social Security later would push the same dollars into a higher bracket, make 85% of Social Security benefits taxable, and risk her first IRMAA Medicare surcharge at the $106,000 income threshold.

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.

This is the piece that quietly rescues the plan (a fuller walkthrough of the timing lives inside The Social Security Decision). By the time RMDs hit at 75, her traditional balance is smaller, her Roth is meaningful, and her Social Security check is 32% larger than it would have been at full retirement age.

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 easily.

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. Withdraw enough to fill the 12% bracket, then decide whether a partial Roth conversion into the 22% bracket still beats the future tax cost of leaving the money in traditional.
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. If a large withdrawal or conversion is coming, model the premium surcharge before you sign the paperwork.

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