Full $1 Million Roth Conversion Can Trigger $167,000 Tax Hit and Medicare Surcharges
Updated
Updated · Yahoo Finance · Aug 11
Full $1 Million Roth Conversion Can Trigger $167,000 Tax Hit and Medicare Surcharges
3 articles · Updated · Yahoo Finance · Aug 11
Summary
$1 million converted to a Roth IRA at once can saddle a 63-year-old couple with nearly $167,000 in immediate costs, including taxes and later Medicare surcharges.
Vanguard's example assumes $100,000 of other income, which pushes the conversion into a roughly $160,000 upfront tax bill because every converted dollar is taxed as ordinary income in that year.
That income spike can also trip Medicare's IRMAA rules: a conversion at 63 is counted in the two-year lookback and would place the couple in the highest surcharge bracket at 65.
At 2026 rates, that means $689.90 a month for Part B and $91 for Part D for that year, adding a combined $6,936 above the baseline.
The warning is that affluent savers trying to maximize tax-free growth can erode seven-figure long-term wealth if they convert too much in a single year.