A 70-Year-Old With $1.4 Million Faces a $62,000 RMD That Pushes Him Into a Higher Tax Bracket

At 70, he feels fine. Social Security covers the basics, his IRA is growing, and a $40,000 annual withdrawal keeps things comfortable. But at 73, the IRS will start requiring minimum distributions from that IRA, and the amount it demands will push him into a higher tax bracket, raise his Medicare premiums, and cost him roughly $4,600 more per year in federal taxes. The window to act is open right now, and it closes before he turns 73.

Why the RMD Math Hits Harder Than It Looks

The required minimum distribution (RMD) system requires IRA owners to withdraw a government-calculated minimum each year starting at age 73, under the SECURE 2.0 Act. (That age-73 trigger applies to people born between 1951 and 1959; those born in 1960 or later must wait until 75.) The logic behind RMDs is straightforward: contributions to tax-deferred retirement accounts come with an immediate income tax deduction, and investments grow without current taxation. The IRS mandates RMDs to ensure that money is eventually taxed as ordinary income rather than deferred forever.

The IRS uses a divisor from the Uniform Lifetime Table to set the annual floor. At 73, that divisor is 26.5. Assuming 5% annual growth on the $1.4 million IRA, the balance reaches approximately $1.62 million by age 73, which puts the first RMD at approximately $61,132. That figure replaces the voluntary $40,000 withdrawal. The IRS simply requires more.

Today, his gross income is $38,400 in Social Security plus $40,000 from the IRA. His income is high enough that 85% of Social Security becomes taxable, and after applying the standard deduction for a single filer over 65, his federal taxable income is approximately $56,000. That produces a federal tax bill of roughly $7,400, keeping him in the 22% bracket.

At 73, the forced $61,132 RMD replaces the $40,000 withdrawal. After Social Security taxation and the standard deduction, taxable income rises to approximately $77,000. The federal tax bill climbs to roughly $12,000, pushing him into the 24% bracket. That is approximately $4,600 more per year in federal taxes, caused entirely by the mandatory withdrawal increase.

For 2026, the 22% bracket for single filers covers taxable income up to $105,700, with the 24% bracket beginning above that threshold. The 2026 standard deduction for single filers is $16,100. Under the One Big Beautiful Bill Act, taxpayers age 65 and older can also claim an additional $6,000 senior deduction for tax years 2025 through 2028. However, that deduction begins phasing out at $75,000 in modified adjusted gross income for single filers, at a rate of 6% per dollar above that threshold. With gross income already above $75,000, this person receives only a partial benefit at current income levels, and during high-conversion years the deduction would shrink further.

The IRMAA Cliff Is the Hidden Risk

The bracket problem is manageable. The Medicare surcharge risk is the one that can catch retirees off guard.

IRMAA (Income-Related Monthly Adjustment Amount) is a Medicare premium surcharge that applies when modified adjusted gross income crosses a threshold. For 2026, that threshold for a single filer is $109,000. At $99,532 in gross income at age 73, he sits uncomfortably close to that line.

One strong market year could push the IRA to $1.8 million, forcing an RMD of over $68,000 and pushing total income above $109,000. At that point, the first IRMAA surcharge tier adds $81.20 per month to Part B premiums and $14.50 per month to Part D premiums, totaling roughly $1,148 per year in extra Medicare costs on top of the higher tax bill. Because IRMAA is assessed based on income from two years prior, a single high-income year at 71 or 72 can trigger surcharges at 73, before the retiree has any chance to adjust.

Three Years to Act: The Roth Conversion Window

Between ages 70 and 72, he has three full tax years in which he controls his IRA withdrawals entirely. No RMD is required. That is the conversion window. The strategy is to convert a portion of the traditional IRA to a Roth IRA each year. Conversions are taxable in the year they occur, but Roth accounts carry no RMDs and produce no taxable income in retirement. Every dollar converted now is a dollar the IRS cannot force out later.

The target is to convert enough to bring the IRA balance down to a level where the age-73 RMD stays below the IRMAA threshold. Converting $80,000 per year for three years reduces the IRA by $240,000 (before accounting for taxes paid on conversions), keeping the projected RMD under control. Conversion amounts must also be sized carefully against the OBBBA senior deduction phase-out: adding $80,000 to income during conversion years pushes MAGI well above $75,000, which reduces or eliminates that deduction. A tax planner can model the interaction of both thresholds simultaneously.

Here is what the approach looks like, year by year:

1. Age 70 (Year 1): Convert $80,000 from a traditional IRA to Roth. This adds $80,000 to taxable income on top of the existing $40,000 withdrawal and Social Security. Sizing the conversion carefully can keep total income within the 22% bracket. Paying tax now at a known rate is preferable to paying at an unknown future rate.
2. Age 71 (Year 2): Repeat the $80,000 conversion. Monitor the IRA balance and adjust if the portfolio grows faster than expected. The goal is to stay below the ceiling of the 22% bracket while chipping away at the pre-tax balance.
3. Age 72 (Year 3): Final conversion year before RMDs begin. Convert the remaining amount needed to bring the projected age-73 balance below the level that would trigger an IRMAA surcharge. After three years, the IRA is smaller, the Roth is funded, and forced distributions at 73 are meaningfully reduced.

Converting at 22% today beats being forced to withdraw at 24% or higher for the next 20 years, with Medicare surcharges compounding on top.

What to Do First

Calculate the exact conversion amount that keeps taxable income at the top of the 22% bracket each year. With the 22% bracket running to $105,700 in taxable income for 2026 single filers, there is room to convert meaningfully without crossing into 24%. The most common mistake is waiting. Once RMDs begin at 73, they cannot be converted directly to a Roth. They must be taken as taxable income first, and only remaining balances can then be converted. The conversion window is the years before RMDs start, and it does not return.

A fee-only tax planner is worth the investment here. The optimal conversion amount depends on projecting IRA growth, Social Security taxation thresholds, IRMAA brackets, and now the OBBBA senior deduction phase-out, all at the same time. The stakes span tens of thousands of dollars over a 15- to 20-year retirement. Getting the conversion sizing right, with professional input, is likely the highest-return financial decision available during this window.

Editor’s note: This update added verified 2026 IRMAA surcharge figures showing that crossing the $109,000 single-filer threshold triggers approximately $1,148 per year in combined Part B and Part D surcharges, and added new context on the OBBBA senior deduction phase-out, which begins at $75,000 MAGI for single filers at a 6% rate and can reduce or eliminate the $6,000 benefit during high-income Roth conversion years.

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