Medicare IRMAA calculator

Yes, with a 2-year delay. Medicare Part B and Part D premiums are income-adjusted using your modified adjusted gross income (MAGI) from two tax years earlier, and a Roth conversion increases that MAGI dollar for dollar. A conversion made in 2026 is the exact income figure used to set your premiums for 2028. The surcharge appears nowhere on your tax return; it arrives two years later as a higher monthly Medicare premium.

IRMAA stands for Income-Related Monthly Adjustment Amount. It is a statutory surcharge added to Medicare Part B (medical insurance) and Part D (prescription drug coverage) premiums for beneficiaries whose modified AGI exceeds federal thresholds under SSA §1839(i). It is structured as a series of cliff-shaped tiers, so earning even $1 over a threshold triggers the full surcharge for the entire 12-month calendar year.

Age 63 for most individuals. Medicare eligibility begins at 65 and the income test looks back 2 years, so the tax year you turn 63 is the first year a conversion can increase your Medicare premiums. Conversions executed at age 62 and younger have zero IRMAA impact. If you delay Medicare enrollment past 65 due to active employer coverage, the lookback window shifts accordingly.

IRMAA is a strict cliff. The surcharge is a flat monthly dollar amount per tier, not a percentage rate applied to excess income. Exceeding a tier threshold by $1 triggers the full additional monthly surcharge across all 12 months for each enrolled beneficiary in the household.

IRMAA MAGI is calculated as Adjusted Gross Income (AGI from Form 1040, Line 11) plus tax-exempt municipal bond interest (Line 2a). This includes taxable Roth conversions, pre-tax 401(k)/IRA withdrawals, Required Minimum Distributions (RMDs), capital gains, dividends, wages, pensions, and the taxable portion of Social Security. The standard deduction does NOT reduce IRMAA MAGI.

Yes, 100% of tax-exempt interest is added back into MAGI for IRMAA calculations under IRC §1839(i)(4)(C). Holding municipal bonds will reduce your federal income taxes, but will not shield you from Medicare IRMAA surcharges.

Twice if both spouses are enrolled in Medicare. While the income threshold is tested against the combined Modified AGI on a Married Filing Jointly return, the resulting monthly surcharge is assessed per enrolled beneficiary, doubling the household cost.

Married individuals who lived together at any time during the tax year and file separately face severely punitive IRMAA rules. The MFS schedule contains only three tiers: income up to $109,000 pays no surcharge, but income between $109,000 and $391,000 immediately jumps to Tier 4 surcharges ($446.30/mo Part B + $83.30/mo Part D), bypassing Tiers 1 through 3 entirely.

No. The Social Security Administration (SSA) allows IRMAA appeals on Form SSA-44 only for eight specific Qualifying Life-Changing Events: death of a spouse, marriage, divorce/annulment, work reduction, work stoppage (retirement), loss of income-producing property, loss of pension, or employer settlement. Voluntary Roth conversions, capital gain harvesting, and RMDs are voluntary income events and do not qualify for an appeal.

Yes, if you experienced a "Work Stoppage" or "Work Reduction". If your income from two years prior was high due to peak employment wages and you have since retired, you can file Form SSA-44 with proof of your work stoppage (e.g. employer separation letter) to have Medicare base your premiums on your current, lower retirement income.

Yes, frequently. Because an IRMAA tier surcharge is a fixed annual dollar penalty applied for only one premium year, saving thousands of dollars in ordinary federal income tax by converting inside a low bracket (such as 12% or 22% instead of a future 32%+ bracket driven by RMDs) often dwarfs the temporary IRMAA surcharge.

Under SECURE 2.0, RMDs begin at age 73 (or age 75 for individuals born in 1960 or later). RMDs cannot be rolled over and are treated as mandatory taxable income. Large pre-tax balances force large RMDs that can permanently trap retirees in high IRMAA tiers for the rest of their lives. Executing Roth conversions in your 50s and 60s reduces the pre-tax balance, mitigating future lifetime IRMAA exposure.

CMS publishes official IRMAA income brackets and surcharges each autumn for the following calendar year (roughly one year in advance). Because of the 2-year lookback, the exact statutory schedule that will govern your current tax year conversion does not exist when you make the conversion. The calculator uses the latest published CMS schedule in today's dollars as a conservative benchmark, or allows you to project future brackets forward using CPI-U inflation indexing.