Quick Read – A $1,000 IRA withdrawal in the 22% bracket triggers $850 of Social Security benefits becoming taxable, creating an effective 40.7% marginal rate. – Crossing the $218,000 Medicare IRMAA threshold by $1 costs a couple roughly $2,300 in extra annual premiums,…
tentially pushing marginal cost above 100%. – Retirees can avoid the torpedo’s effective rates of 22.2% to 44.4% by doing Roth conversions before age 73 and drawing from taxable brokerage accounts first. – The IRS publishes seven federal income tax brackets, yet some retirees face an effective 40.7% marginal rate that appears nowhere on that schedule. Yet that is the effective rate some retirees pay on a $1,000 withdrawal from a traditional IRA once Social Security taxes are added
The mechanism is called the tax torpedo, and it turns what looks like a simple 22% bracket into something considerably more expensive. Here is how a $1,000 withdrawal becomes a $407 tax bill. Under the Social Security taxation formula, once a retiree crosses the upper income threshold, every additional dollar of provisional income causes 85 cents of Social Security benefits to become taxable.
A $1,000 IRA distribution adds $1,000 of ordinary income and simultaneously pulls $850 of previously untaxed Social Security benefits into the taxable column. That is $1,850 of new taxable income. In the 22% bracket, which applies to single filers with taxable income over $50,400 and to married couples filing jointly with taxable income over $100,800 in 2026, the resulting tax is $407.