Medicare IRMAA explained: how income raises your Part B and Part D premiums

Most Medicare enrollees pay the standard Part B premium of $202.90/month in 2026. But if your income exceeded certain thresholds in 2024, you pay more — sometimes much more. The income-related monthly adjustment amount (IRMAA) can add up to $487.00/month per person to your Part B premium, and up to $91.00/month to your Part D premium.^[2][3] For a married couple both on Medicare at the top tier, that is over $13,872/year in surcharges above the standard premium. This guide explains how Medicare Parts A, B, C, and D fit together, when to enroll, how IRMAA is calculated, why Roth conversions often trigger surprises, and how to appeal when a life-changing event lowers your income.

Medicare Parts A, B, C, and D in plain English

Part A is hospital insurance. It covers inpatient hospital stays, skilled nursing facility care (with limits), hospice, and some home health services. Most people who worked and paid Medicare taxes for at least 40 quarters receive Part A without a monthly premium. Part A does not use IRMAA; high income does not create a Part A surcharge the way it does for Parts B and D.^[1]

Part B is medical insurance for outpatient care — doctor visits, preventive screenings, lab work, outpatient surgery, and durable medical equipment. Nearly everyone who enrolls pays a monthly Part B premium. The standard premium for 2026 is $202.90. Higher earners pay that base plus an IRMAA surcharge.^[2]

Part C is Medicare Advantage. Private insurers offer plans that package Part A and Part B benefits (often with Part D drug coverage and extras such as dental or vision). You still must be entitled to Part A and enrolled in Part B. Advantage plan premiums vary, but Part B IRMAA still applies on top of whatever the plan charges.

Part D is prescription drug coverage, available as a standalone plan with Original Medicare or as part of many Advantage plans. Plan premiums differ by carrier and formulary. Separately, higher-income enrollees pay a Part D IRMAA surcharge that Social Security collects — it is not optional once you have Part D and your MAGI exceeds the threshold.^[4]

Enrollment windows that matter

Your Initial Enrollment Period usually runs for seven months around your 65th birthday — three months before the month you turn 65, your birthday month, and three months after. Enrolling during that window helps you avoid late-enrollment penalties for Part B and Part D if you lack other creditable coverage. The annual Open Enrollment Period (October 15–December 7) lets you switch Advantage and Part D plans for the following year. People with qualifying employer or union coverage may delay Part B without penalty and use a Special Enrollment Period when that coverage ends.^[1]

IRMAA is not an enrollment choice — it is an income-based premium adjustment that attaches once you are enrolled in Part B or Part D. Delaying Part B while you have creditable employer coverage can postpone the surcharge, but the look-back year still uses earlier MAGI once you enroll. High earners who work past 65 should model both the timing of Part B enrollment and the income years that will set their first IRMAA tiers.

How IRMAA works: the 2-year look-back

The IRS reports your MAGI to CMS each year with a two-year lag. Your 2026 Medicare premiums are based on 2024 income. That lag is why a large Roth conversion, business sale, or capital-gains harvest today can raise Medicare costs two years from now — often after you have already enrolled and started budgeting around the standard premium.^[3]

MAGI for IRMAA is adjusted gross income plus tax-exempt interest (commonly associated with Form 1040 line 2a). Roth conversion income counts. Social Security benefits that are taxable count. Qualified plan distributions count. Municipal bond interest counts. Qualified Roth IRA distributions generally do not. The definition is close to other federal MAGI concepts but always confirm against SSA and CMS materials for your situation.^[6]

CMS notifies you by mail in November or December before the premium year begins. If you are newly enrolled in Medicare, your first-year surcharge may be estimated until IRS data catches up. The Social Security Administration administers IRMAA collection — it is usually deducted from your Social Security benefit check, or billed directly if you do not receive Social Security yet.

2026 IRMAA thresholds and surcharges

The tables below show 2026 Part B and Part D IRMAA tiers using 2024 MAGI. Part B totals equal the standard premium of $202.90 plus the surcharge for that tier. Amounts are monthly and per person enrolled.^[2]

Single / Head of Household

Married Filing Jointly

Married filing separately faces a much stricter structure — any MFS filer with MAGI over $109,000 immediately jumps toward the second-highest surcharge tier. That compressed schedule is a significant penalty for couples who file separately while both are on Medicare.

Run your own numbers with the IRMAA calculator, which highlights your tier and warns when you are within $10,000 of the next cliff.

IRMAA and Roth conversions

Roth conversions are the most common surprise IRMAA trigger. A large conversion in one year adds to MAGI and can push you into a higher IRMAA tier two years later — after the tax bill on the conversion itself is already paid. Optimal conversion planning considers not just the income tax on the conversion, but the IRMAA bracket it may trigger in the following two years.

Use the Roth conversion calculator to estimate conversion tax, and read when to do a Roth conversion for strategy context. Remember that IRMAA thresholds are cliffs, not tapers: a conversion that pushes MAGI just over a tier costs the full tier surcharge for the whole year, not a partial amount. “Bracket bumping” that looks minor on a tax projection can cost hundreds of dollars per month in Medicare premiums for each spouse enrolled.

How to appeal IRMAA: the life-changing event form

If your 2024 income was unusually high and 2026 income is materially lower, you can request a reduction using SSA Form SSA-44. Qualifying life-changing events include marriage, divorce, death of a spouse, work stoppage or reduction, loss of income-producing property, loss of pension, and certain employer settlement payments.^[5]

“Income reduction” alone — because you converted a 401(k) or sold a business — is not a qualifying event. You need a life-changing event from the SSA’s defined list. When an appeal is accepted, Social Security can use more recent tax-year income (or a current-year estimate) instead of the standard look-back year. Contact the Social Security Administration directly, or submit Form SSA-44 by mail with supporting documentation.

IRMAA and Medicare Advantage (Part C)

Part C (Medicare Advantage) plans have their own premiums, but IRMAA surcharges on Part B still apply on top of any Part C plan premium. IRMAA is assessed on Part B regardless of whether you are in Original Medicare or a Medicare Advantage plan. If your Advantage plan includes drug coverage, Part D IRMAA can apply as well. Choosing Advantage for network or supplemental benefits does not erase income-related adjustments.

Planning ahead: how to manage IRMAA exposure

1. Income smoothing before Medicare enrollment. If you are 60–63 and planning large Roth conversions, model which conversion amounts keep you below the IRMAA cliff two years out. Conversions at 63 affect your premiums at 65 — the first year of Medicare for many people. Spreading conversions across multiple years can avoid a single cliff even when total converted dollars are similar.

2. Using qualified charitable distributions (QCDs). If you are 70½ or older, QCDs from an IRA go directly to charity and are excluded from MAGI — reducing IRMAA exposure while helping satisfy required minimum distributions. The annual QCD limit is inflation-adjusted (often cited near $105,000 for recent years); confirm the current-year cap before planning gifts.

3. Timing asset sales. Capital gains from appreciated assets add to MAGI. Spreading sales over multiple years, or harvesting in lower-income years before Medicare, reduces the chance of a single-year cliff. Pair sales planning with the capital gains tax calculator and IRMAA estimates together.

4. Coordinating with your spouse’s income. For married filing jointly, joint thresholds are roughly double the single thresholds. Plan around household MAGI, not just one person’s wages or conversions. When both spouses are on Medicare, each pays the per-person surcharge — so a cliff mistake costs twice as much at the household level.

Also connect IRMAA planning to claiming decisions with the Social Security estimator and Social Security claiming ages guide, and to distribution rules with the RMD calculator.

Frequently asked questions