The tax you pay depends on the amount converted and your total taxable income for the year. The converted amount is added to your ordinary income and taxed at your marginal rate.
For example, if you’re married filing jointly with $150,000 in income and convert $50,000, that conversion would be taxed at the 22% rate (based on 2026 tax brackets), resulting in approximately $11,000 in additional federal tax. Additionally, you would be just below the IRMAA threshold so you would not pay any additional Medicare premiums. Strategic planning can help you convert amounts that will keep you in your current or next-lowest bracket — rather than pushing you into significantly higher rates.