How a 73-Year-Old’s First RMD Suddenly Pushed Her Effective Tax Rate to 40 Percent

The Situation Most Retirees Don’t See Coming

A single 73-year-old retiree collects $30,000 a year from Social Security, holds $980,000 in a traditional IRA, and keeps another $250,000 in a regular brokerage account. On paper, she looks financially set.

At 73, the IRS requires her to start withdrawing from the traditional IRA every year for the rest of her life. That first required minimum distribution (RMD) reshapes her tax picture.

The pattern shows up on retirement forums every spring. Someone who thought they had careful tax planning suddenly discovers a federal tax bill far higher than the 12% bracket they had counted on.

Where the 40% Comes From

The IRS Uniform Lifetime Table divides her IRA balance by 26.5 in the year she turns 73. On $980,000, that produces a first required minimum distribution of about $36,981.

That distribution adds to her ordinary income and drags her Social Security into taxable territory. Above $34,000 of provisional income for a single filer, up to 85% of benefits become taxable. Her provisional income lands near $52,000, so 85% of her $30,000 benefit, or $25,500, now counts as income.

After the IRA distribution and taxable Social Security, less a standard deduction of $18,150 for a single filer over 65 in 2026, combining the $16,100 base and the $2,050 additional deduction for those 65 and older, taxable income lands near $44,331. Her federal tax comes in around $5,072, entirely inside the lower brackets.

The trap emerges on the next dollar. Every additional dollar from the IRA drags another $0.85 of Social Security into taxable income, so each new dollar of withdrawal produces $1.85 of new taxable income. Once she crosses into the 22% bracket, which begins at $50,400 of single taxable income in 2026, that multiplier produces an effective marginal rate of roughly 40.7%.

That is the tax torpedo, and her first RMD parked her inside its blast radius.

How the Other Pieces Connect

Two outside forces tighten the squeeze. The federal funds rate sits at 3.75% and the 10-year Treasury yields about 4.49%, so any cash or bonds in her brokerage throw off taxable interest that feeds the provisional income calculation. Medicare’s Income-Related Monthly Adjustment Amount (IRMAA) surcharges begin at $109,000 of modified adjusted gross income (MAGI) for a single filer, where even a dollar over a tier can add more than $1,000 a year in Part B and Part D premiums.

Three tools matter most:

1. Qualified charitable distributions. Money sent directly from the IRA to a qualified charity counts toward the RMD but never appears in adjusted gross income. It is the cleanest way to satisfy the rule without feeding the torpedo.
2. Brokerage basis and the step-up at death. Spending from brokerage cost basis, or holding appreciated stock so heirs receive a stepped-up basis, avoids piling new ordinary income on top of the RMD.
3. Bracket-aware Roth conversions before 73. The torpedo is the strongest argument for partial Roth conversions in the 60s. Every dollar converted in those quieter years is a dollar that never shows up in a future RMD.

What to Take From This

The mistake hardest to undo is assuming the bracket on the IRS table is the rate that matters. For a retiree drawing Social Security alongside a traditional IRA, the real marginal rate on the next withdrawal is often nearly double the printed one.

Before any large withdrawal, capital gains harvest, or Roth conversion, model what that decision does to provisional income, the Medicare surcharge tier, and next year’s return together, a point The New York Times has made in its coverage of managing RMDs in a volatile market. Which account a dollar comes from can move the answer by thousands. A tax preparer who runs the numbers both ways usually earns the fee back in the first conversation.