How this calculator works
Medicare charges higher Part B and Part D premiums when your income from two years earlier exceeds statutory thresholds. That extra cost is the Income-Related Monthly Adjustment Amount (IRMAA). This calculator maps your modified adjusted gross income (MAGI) and filing status to the published 2026 IRMAA tiers so you can see the monthly Part B premium, Part D surcharge, and annual household surcharge before you enroll or before you finalize a large taxable event.
CMS uses a two-year look-back. For 2026 premiums, the agency relies on 2024 MAGI reported to the IRS. Enter the MAGI from that look-back year — typically adjusted gross income plus tax-exempt interest. Roth conversions, traditional IRA and 401(k) withdrawals, capital gains, taxable Social Security, and municipal bond interest generally count. Qualified Roth IRA distributions do not.
Filing status matters. Single and head-of-household thresholds differ from married filing jointly, and married filing separately faces a compressed structure that jumps quickly into high surcharge tiers. When both spouses are on Medicare and you file jointly, check both on Medicare so household totals double the per-person surcharges — IRMAA is assessed per enrollee, not once for the couple.
What IRMAA covers
Part B covers outpatient care, doctor visits, preventive services, and durable medical equipment under Original Medicare. Everyone enrolled in Part B pays at least the standard monthly premium; IRMAA adds a fixed monthly surcharge on top when income is high enough. Part D prescription drug plans have their own plan premiums; IRMAA adds a separate monthly drug surcharge that Social Security collects alongside Part B.
Medicare Advantage (Part C) plans replace Original Medicare Part A and B benefits through private insurers. Choosing Advantage does not remove Part B IRMAA. You still owe the income-related Part B adjustment (and Part D IRMAA if you have drug coverage) on top of any plan premium.
Cliffs, not phase-outs
IRMAA thresholds are cliffs. Crossing a bracket by one dollar moves you into the full surcharge for that tier for the entire premium year. There is no partial surcharge for being slightly over the line. That design is why proximity warnings matter: if your MAGI sits within about $10,000 of the next threshold, a modest Roth conversion, capital gain, or bonus can create a full year of higher premiums two years later.
Use this tool together with the Roth conversion calculator when you are modeling conversions in your early 60s. Conversions at age 63 affect Medicare premiums at 65, your first typical enrollment year. The income tax estimator helps separate ordinary income tax from the later IRMAA cash-flow hit.
Planning context
IRMAA is deducted from Social Security benefits when you receive them, or billed directly if you are not yet collecting. Notices usually arrive in late fall before the premium year. If a life-changing event — retirement, divorce, death of a spouse, work reduction — permanently lowers income after the look-back year, Form SSA-44 may let Social Security use more recent income. A one-time Roth conversion or asset sale alone is not a qualifying event.
Strategies that often reduce exposure include smoothing conversions across years, using qualified charitable distributions after age 70½ to keep RMDs out of MAGI, spreading capital gains, and coordinating household MAGI for married filers. None of those tactics opt you out of IRMAA if you remain enrolled and over the threshold — they only change whether you cross a cliff.
Read the full walkthrough in Medicare IRMAA explained, including Part A/B/C/D basics, enrollment windows, appeal rules, and the complete tier tables. Pair IRMAA planning with the Social Security estimator and RMD calculator so Medicare premiums, benefit claiming, and required distributions stay in one retirement cash-flow picture.
Common mistakes
Using this year’s projected income instead of the look-back year. Enter the MAGI year CMS will actually use (two years before the premium year).
Ignoring spouse enrollment. Household surcharge totals only double when both spouses are on Medicare; one enrollee pays one surcharge.
Treating IRMAA like a tax bracket phase-out. Crossing the line costs the full tier surcharge for the year.
Forgetting Part D. Part B gets the most attention, but Part D IRMAA is a separate monthly add-on for higher-income enrollees with drug coverage.
Assuming Medicare Advantage avoids IRMAA. Part B IRMAA still applies under Advantage plans.
If you are still working past 65 and delaying Part B because you have qualifying employer coverage, remember that high earnings in the look-back years can still produce IRMAA once you enroll. The surcharge starts with Part B or Part D enrollment — not with claiming Social Security — but the income that sets the tier may have been earned while you were still fully employed.
Results are estimates for education and planning. Confirm official premiums, MAGI definitions, and appeal deadlines with Medicare and the Social Security Administration before making enrollment or tax decisions. Thresholds and surcharge amounts are updated annually; re-check after each November CMS announcement.
FAQ
Which year's income is used for 2026 IRMAA?
CMS uses 2024 income (MAGI) to determine 2026 IRMAA surcharges. This 2-year look-back is why income planning before Medicare enrollment matters — a high-income year now affects premiums two years later.
What income counts as MAGI for IRMAA?
MAGI for IRMAA = adjusted gross income + tax-exempt interest. Roth conversions, traditional IRA withdrawals, capital gains, taxable Social Security benefits, and municipal bond interest all count. Roth IRA qualified distributions do not.
Does the surcharge apply per person or per household?
IRMAA is assessed per person enrolled in Medicare. A married couple where both spouses are on Medicare each pay the surcharge applicable to their household MAGI — so the joint household cost is double the per-person figure.
Can I appeal if my income dropped significantly?
Yes. If a qualifying life-changing event (marriage, divorce, death of spouse, retirement, work reduction) caused your income to drop after the look-back year, you can file SSA Form SSA-44 to request a reduction based on more recent income.
Do IRMAA surcharges apply to Medicare Advantage plans?
Yes. Part B IRMAA surcharges apply regardless of whether you're in Original Medicare or a Medicare Advantage (Part C) plan. You pay the IRMAA surcharge on top of any Medicare Advantage plan premium.
Do qualified charitable distributions (QCDs) reduce MAGI for IRMAA?
Yes. QCDs from a traditional IRA (available at age 70½+) go directly to charity and are excluded from AGI, so they do not increase MAGI for IRMAA the way a taxable IRA withdrawal would. That can help keep you under the next IRMAA cliff — confirm amounts and eligibility with SSA/CMS and a tax professional.