What is IRMAA?

IRMAA (Income-Related Monthly Adjustment Amount) is a surcharge added to your Medicare Part B and Part D premiums when your income rises above set thresholds. For 2026, it applies if your modified adjusted gross income (MAGI) from your 2024 tax return was above $109,000 on an individual return or $218,000 on a joint return.

IRMAA is not a tax. It is the higher-income share of your Medicare premiums, determined by the Social Security Administration (SSA) from IRS data and usually deducted from your Social Security benefit. It is also separate from the Medicare tax, the payroll tax withheld from your wages as part of FICA. According to the Centers for Medicare & Medicaid Services (CMS), roughly 8% of people with Medicare Part B pay it.

IRMAA Brackets for 2026

Each tier adds a fixed monthly amount on top of the 2026 standard Part B premium of $202.90 and on top of whatever your Part D plan charges. The income column is your 2024 MAGI.

All amounts are monthly and per person. The joint-return thresholds are measured against the couple’s combined MAGI, but each spouse enrolled in Medicare pays the surcharge separately, so a couple who are both on Medicare pay it twice.

Married couples who file separate returns face a much steeper 2026 schedule. With 2024 MAGI above $109,000 and under $391,000, the Part B surcharge is $446.30 and the Part D surcharge is $83.30. At $391,000 or more, they rise to $487.00 and $91.00.

The Part D surcharge applies whether your drug coverage comes from a standalone Part D plan, a Medicare Advantage plan with drug coverage, or an employer-sponsored Medicare Part D plan. Employer or retiree drug coverage that isn’t a Part D plan doesn’t carry the surcharge. It is paid to Medicare, not to your plan.

How IRMAA Is Calculated

For most taxpayers, IRMAA MAGI is your adjusted gross income plus tax-exempt interest income, the figures on lines 11 and 2a of the 2024 Form 1040, the return used for 2026 premiums:

IRMAA MAGI = Adjusted Gross Income + Tax-Exempt Interest

The statute also adds back a few less common exclusions: excluded savings bond interest used for education, the foreign earned income and housing exclusions and the foreign housing deduction, and certain U.S. possession income.

The add-back means municipal bond interest, though free of federal income tax, still counts toward your Medicare premium tier. This definition differs from the MAGI used for Roth IRA eligibility or Affordable Care Act (ACA) subsidies, so a number you calculated for one of those purposes may not match.

Because the starting point is AGI, anything that raises AGI can raise IRMAA: wages, traditional IRA and 401(k) withdrawals, required minimum distributions, pension income, realized capital gains, dividends, and Roth conversions. Qualified Roth withdrawals and qualified Health Savings Account (HSA) distributions don’t appear in AGI and don’t count.

The Two-Year Lookback

SSA uses the most recent tax data the IRS can provide, which is generally from two years before the premium year and never more than three. Your 2026 premiums are based on 2024 income, 2027 premiums on 2025 income, and 2028 premiums on the income you report for 2026.

The lookback means IRMAA planning starts before you enroll. If you go on Medicare at 65, your first year’s premium is set by your income at 63. A large bonus, business sale, or Roth conversion in that year can raise premiums you haven’t started paying yet. Hovering over your projected income on ProjectionLab’s Optimize graph shows your IRMAA MAGI against your chosen cliff each year, which makes a one-off spike like a home sale easy to catch before it becomes a surcharge.

The IRMAA Cliff

IRMAA tiers are not marginal. Crossing a threshold by a single dollar applies the full surcharge for that tier to every month of the year, which is why each threshold is often called a cliff.

Take a married couple, both on Medicare, who file jointly. Their 2024 MAGI was $219,000, just $1,000 over the first 2026 threshold. Each spouse owes an extra $81.20 a month for Part B and $14.50 for Part D, or $95.70 a month. Over 12 months that is $1,148.40 per person and $2,296.80 for the couple, all triggered by $1,000 of income.

The jumps aren’t uniform. The first Part B tier adds $81.20 a month, each of the next three adds $121.70, and the top tier adds $40.70; the Part D steps are $14.50, $23.00, $22.90, $22.90, and $7.70. At $274,000 of joint MAGI, the Part B surcharge is $81.20; at $274,001 it is $202.90.

How to Avoid IRMAA

Avoiding IRMAA comes down to controlling which years carry your income. The tools are the same ones used in general tax planning, judged against a cliff instead of a bracket.

Start with Roth conversions, since their size and timing are entirely up to you. Conversions in tax years at least three years before your first Medicare year generally won’t land in an IRMAA lookback year (SSA can fall back to a three-year-old return when newer data isn’t available), and shrinking traditional balances early also reduces the RMDs that can push you over a threshold later. Once you’re inside the lookback window, conversions can still make sense, but sizing each one to stop just below a threshold avoids paying a full tier for a small overshoot.

Large one-time gains can often be spread out. Selling a concentrated stock position or a rental property over two or more tax years can keep each year below a threshold that a single sale would cross.

From age 70 1/2, IRA money sent directly to charity as a qualified charitable distribution (QCD) counts toward your RMD but stays out of AGI. And in years when income is already high, qualified Roth withdrawals add nothing to MAGI, while spending from a taxable account adds only the realized gain, not the full withdrawal.

Whether staying below a cliff is worth it depends on what it costs. Capping a Roth conversion to keep a couple at $218,000 and save $2,296.80 in surcharges can backfire if it leaves larger traditional balances to be taxed at a higher rate later. If you set an IRMAA Cliff target in ProjectionLab’s tax optimizer, your Roth conversions, withdrawals, and gain harvesting are held below the tier you pick, and you can compare that plan against one that accepts the surcharge.

How to Appeal IRMAA: Life-Changing Events and Form SSA-44

Because IRMAA looks back two years, it can charge you for income you no longer have. SSA will make a new determination using a more recent year’s income, or an estimate of the current year’s, if your income dropped because of a qualifying life-changing event:

• Marriage, divorce, or annulment
• Death of a spouse
• Work stoppage or reduced work hours, for you or your spouse
• Loss of income-producing property due to an event beyond your control, such as a natural disaster, arson, or criminal theft
• Loss of employer pension income through the plan’s termination, reorganization, or scheduled cessation
• A settlement payment from a current or former employer because of its closure, bankruptcy, or reorganization

Retiring counts as a work stoppage, which covers the common case of a lookback year that still includes a full salary. You request the new determination on Form SSA-44, with documentation of the event and of the lower income.

Some income drops don’t qualify. SSA lists the voluntary sale of income-producing property, ordinary loss of dividend income, higher medical or living expenses, and loss of alimony or child support as events that are not life-changing.

Separately, you can ask SSA for a new determination if you filed an amended return for the lookback year or the IRS data was wrong. If you disagree with the determination itself, you can file a request for reconsideration on Form SSA-561.

Frequently Asked Questions

What does IRMAA stand for? Income-Related Monthly Adjustment Amount. It is the extra amount higher-income Medicare enrollees pay on top of the standard Part B premium and their Part D plan premium.

Is IRMAA calculated every year? Yes. SSA redetermines it each year from the newest tax return the IRS provides, so a single high-income year affects only the premium year that looks back to it. If your income falls, the surcharge drops off on its own once that lower year becomes the lookback year.

Is IRMAA based on AGI? Partly. IRMAA uses AGI plus tax-exempt interest income, so two people with the same AGI can land in different tiers if one holds municipal bonds.

Does Social Security count towards IRMAA? Only the taxable portion. Up to 85% of your Social Security benefit can be included in AGI depending on your other income, and whatever share is included counts toward IRMAA.

When does IRMAA kick in? For 2026, above $109,000 of 2024 MAGI on an individual return or $218,000 on a joint return. The surcharge starts with your first Medicare premium, so income from two years before you enroll matters.

What are the IRMAA brackets for 2027? CMS had not published them as of October 2, 2026. The 2026 figures were announced on November 14, 2025, and the 2027 brackets will apply to income from your 2025 tax return.

Does IRMAA apply to Medicare Advantage? The Part D surcharge does if your Medicare Advantage plan includes drug coverage. The surcharge applies to Medicare Part D coverage, whether through a standalone plan, a Medicare Advantage plan, or an employer-sponsored Part D plan. Employer group drug coverage that isn’t Part D doesn’t carry it.