IRMAA Medicare Calculator.

IRMAA stands for Income-Related Monthly Adjustment Amount. It’s a surcharge that higher-income Medicare beneficiaries pay on top of the standard Part B and Part D premiums. The Social Security Administration determines your IRMAA based on your Modified Adjusted Gross Income (MAGI) from two years prior — so your 2024 tax return determines your 2026 premiums.

MAGI for IRMAA purposes is your adjusted gross income plus tax-exempt interest income (line 2a of Form 1040). This means municipal bond interest counts toward IRMAA even though it’s not taxable. Capital gains from selling a home, exercising stock options, or large Roth conversions can all push you into a higher IRMAA tier for two years.

IRMAA is assessed per person. If both spouses are on Medicare and file jointly, you each pay the surcharge — doubling the total cost. The surcharge is deducted directly from your Social Security benefit or billed quarterly if you don’t receive Social Security.

Form SSA-44: Life-changing events

If your income dropped significantly due to a life-changing event — retirement, divorce, death of a spouse, loss of income-producing property, or reduction in pension income — you can file Form SSA-44 with the Social Security Administration to request a reduction or elimination of IRMAA using your current-year income instead of the two-year lookback. This can save thousands in surcharges during the transition year.