A 62-year-old just walked out of a corporate job with $1.6 million in a traditional 401(k), a paid-off house, and no plans to touch Social Security for eight more years. The tax code sees a rare window: reported income can be almost anything the retiree wants it to be, before required minimum distributions at 73 and delayed Social Security at 70 lock the outcome in for good.
From 62 to 70, with no wages and no Social Security, taxable income drops to whatever spins off a brokerage account plus voluntary Roth conversions. That eight-year gap is the only stretch of adult life most high savers ever see the 10% and 12% federal brackets from the inside. For context, the average Baby Boomer 401(k) balance sits near $267,900, so a $1.6 million balance is squarely in the top tier where this planning pays off the most.
Filling the 12% Bracket
For a married couple filing jointly in 2026, the standard deduction is $32,200, and the 12% bracket runs up to $100,800 of taxable income. Stack those together and roughly $133,000 of gross income can come off the 401(k) each year at a blended federal rate under 11%. Most retirees at this balance do not need that much cash. They need a conversion size that moves meaningful money without punching into 22%.
Convert $38,750 per year from the traditional 401(k) into a Roth IRA for eight straight years and $310,000 lands in a bucket that never triggers an RMD, never counts toward Social Security taxation, and never lifts a Medicare premium again. At today’s 10-year Treasury yield near 4.6%, that Roth balance alone can throw off tax-free interest roughly equal to a middle-class Social Security check. A composite I-bond rate near 4.3% held inside a taxable account can bridge cash needs during conversion years without adding to reportable income.
The Delayed Credit That Rewires the Math
Every year Social Security is delayed past full retirement age, the benefit grows 8% until 70. For someone with a full retirement age of 67, waiting three extra years turns a $3,000 monthly check into $3,720, a 24% permanent raise indexed to inflation. The 2026 COLA came in at 2.8%, and every future COLA compounds on the larger base.
Roth conversions and taxable-account withdrawals from 62 to 70 fund living expenses while delayed retirement credits accrue. Those same conversions shrink the pretax balance, which lowers the RMD at 73 and reduces the odds that 85% of Social Security ends up taxable once benefits start.
The IRMAA Landmine at 63
Medicare’s Income-Related Monthly Adjustment Amount uses a two-year lookback. A conversion done at 63 shows up on the 65-year-old’s Part B premium. Cross the first IRMAA tier and premiums jump roughly about $70 per month per person; cross higher tiers and the surcharge climbs past several hundred dollars each. Sizing conversions to stay under that first cliff is often more valuable than filling the entire 12% bracket. This is where the eight-year plan gets personal, and where running the numbers against a specific balance beats a rule of thumb.
The calculator shows the split most 62-year-olds miss: the tax paid on conversions today is almost always smaller than the tax that would hit the same dollars once they land on top of Social Security and RMDs at 73.
Three Moves Before Year-End
- Pull last year’s tax return and calculate the exact room under the top of the 12% bracket after standard deduction and any other income. That precise dollar figure is the annual conversion target for the next eight years.
- Confirm whether high-earner status in 2025 W-2 wages will force any remaining 401(k) catch-up contributions into a Roth 401(k) under the SECURE 2.0 rule that took effect January 1 for employees earning more than $150,000. That rule already pushes catch-up money in the right direction.
- Ask the 401(k) plan whether in-plan Roth conversions are permitted, or whether the money has to roll to an IRA first. Some plans only allow full rollovers, which forces an all-or-nothing decision on the rest of the pretax balance.
Treat the $1.6 million balance at 62 as raw material. What comes out of the eight years between 62 and 70 (how much sits in Roth, how large the Social Security check is at 70, how small the RMD is at 73) is the actual retirement.
Contact [email protected] for any questions or corrections.
Top Gaining Stocks
Top Losing Stocks