Medicare IRMAA explained: what triggers it and how to avoid the cliffs

IRMAA (Income-Related Monthly Adjustment Amount) is a surcharge added to Medicare Part B and Part D premiums for higher-income beneficiaries. It is calculated using your modified adjusted gross income from two years prior. Understanding the IRMAA thresholds, and how income decisions like Roth conversions and RMDs can push you across them, is an important part of retirement income planning.

What is IRMAA?

IRMAA stands for Income-Related Monthly Adjustment Amount. It is an extra charge that Medicare adds to your Part B and Part D premiums if your income exceeds certain thresholds. The standard 2026 Part B premium is $202.90 per month. If your income is above the base threshold, IRMAA adds to that, and the higher your income, the larger the surcharge.

IRMAA exists because Medicare is a means-tested program in this respect: higher earners are expected to pay a larger share of their own coverage costs. It is not a penalty in the legal sense, but it can feel like one if it catches you off guard.

The two-year lookback: why this year's income affects your premiums later

Here is the part that trips up a lot of retirees. Medicare does not look at your current income to set your premiums. It looks at your MAGI (modified adjusted gross income) from two years prior. For 2026 Medicare coverage, Social Security uses your 2024 tax return.

That two-year lag matters a great deal in retirement planning. A Roth conversion, a large withdrawal, or the sale of a property in 2024 could raise your 2026 premiums, even if your income in 2025 or 2026 is much lower. Knowing this in advance is what gives you the chance to plan around it.

The 2026 IRMAA brackets

The brackets below are based on 2024 MAGI and apply to 2026 Medicare coverage. A surcharge applies to both Part B (medical coverage) and Part D (prescription drug plans). Part D surcharges are added on top of whatever your specific plan's premium already is. (Source: Centers for Medicare and Medicaid Services, 2026 Medicare Parts A and B Premiums and Deductibles fact sheet, published November 14, 2025; Medicare.gov, current as of July 13, 2026. These figures apply to 2026 coverage and are adjusted annually, so check CMS or Medicare.gov for the most current year.)

• Individual MAGI up to $109,000 (married filing jointly up to $218,000): standard Part B premium of $202.90/month, no IRMAA surcharge on Part B or Part D
• Individual MAGI $109,001 to $137,000 (MFJ $218,001 to $274,000): Part B total $284.10/month (IRMAA surcharge $81.20), Part D IRMAA surcharge $14.50/month
• Individual MAGI $137,001 to $171,000 (MFJ $274,001 to $342,000): Part B total $405.80/month (IRMAA surcharge $202.90), Part D IRMAA surcharge $37.50/month
• Individual MAGI $171,001 to $205,000 (MFJ $342,001 to $410,000): Part B total $527.50/month (IRMAA surcharge $324.60), Part D IRMAA surcharge $60.40/month
• Individual MAGI $205,001 to $499,999 (MFJ $410,001 to $749,999): Part B total $649.20/month (IRMAA surcharge $446.30), Part D IRMAA surcharge $83.30/month
• Individual MAGI $500,000 or more (MFJ $750,000 or more): Part B total $689.90/month (IRMAA surcharge $487.00), Part D IRMAA surcharge $91.00/month

A couple enrolled in Medicare and in the second IRMAA tier (the first one above the base) could pay an extra $81.20 each per month on Part B alone, plus Part D surcharges, adding up to more than $2,300 per year in additional premiums. At the highest bracket, the added cost for a couple could be over $13,000 per year above the standard premium. These are not hypothetical numbers for most retirement households.

What counts as MAGI for IRMAA purposes?

For IRMAA, your MAGI is your adjusted gross income plus any tax-exempt interest income (such as from municipal bonds). Common items that are included:

• Wages or self-employment income if you are still working
• Taxable Social Security benefits
• Required minimum distributions (RMDs) from traditional IRAs and 401(k)s
• Roth conversion amounts (the amount you convert is added to your ordinary income in that year)
• Capital gains from selling investments, a home, or other assets
• Taxable pension and annuity income
• Tax-exempt interest (this is added back in even though it is not on your regular AGI)

Roth IRA withdrawals, on the other hand, are generally not counted in MAGI, which is one of the reasons Roth accounts can be a useful tool in managing IRMAA exposure over time.

How Social Security notifies you, and your right to appeal

If you are subject to IRMAA, Social Security will send you an initial determination notice explaining the surcharge and the income information they used. You typically receive this notice before your Medicare coverage starts or at the time of your annual adjustment.

If your income has changed significantly since the year being used, you may be able to request a reconsideration using Form SSA-44 (Medicare Income-Related Monthly Adjustment Amount Life-Changing Event). Qualifying life-changing events include retirement or a reduction in work hours, marriage, divorce or annulment, death of a spouse, loss of income from an employer, loss of pension income, and certain other circumstances. This is worth knowing about, because if your income dropped sharply after retirement, the IRMAA determination could be based on income that no longer reflects your situation.

This is general information about a process that exists. Whether an appeal makes sense in your specific case, and how to approach it, is worth discussing with a planner who can look at your actual numbers.

IRMAA and Roth conversions: understanding the connection

One of the most common planning questions around IRMAA comes up in the context of Roth conversions. Many retirees who are considering converting traditional IRA money to a Roth think carefully about the size and timing of those conversions, partly because a conversion that is too large in a given year could push their MAGI across an IRMAA bracket two years later.

The tradeoff is real. A Roth conversion is often still worth doing, especially during the lower-income years between retirement and RMDs at age 73, because future Roth withdrawals do not count toward MAGI at all. But doing a very large conversion in a single year without paying attention to where it lands relative to IRMAA thresholds could create unnecessary surcharges.

RMDs create a similar consideration. Once required minimum distributions begin, you may have less flexibility about your income floor, which makes any additional income, like a capital gain or a large withdrawal, worth modeling carefully before you take it.

None of this means you should avoid conversions or other income-generating decisions. It means these are the kinds of tradeoffs that are worth understanding before you act, and worth discussing with a planner who can model them for your specific situation. For more on how Roth conversions work in your 60s, see our guide to Roth conversions in your 60s.

Frequently asked questions

What is IRMAA?

IRMAA stands for Income-Related Monthly Adjustment Amount. It is a surcharge added to Medicare Part B and Part D premiums for beneficiaries whose income exceeds certain thresholds. For 2026 coverage, Medicare uses your 2024 modified adjusted gross income to determine whether IRMAA applies.

At what income does IRMAA kick in for 2026?

For 2026 Medicare coverage, IRMAA begins for individuals with 2024 MAGI above $109,000 (or above $218,000 for married couples filing jointly). Below those thresholds, the standard Part B premium of $202.90 per month applies with no surcharge.

Can a Roth conversion trigger IRMAA?

It could, if the conversion is large enough to push your modified adjusted gross income above an IRMAA threshold in that tax year. Because IRMAA uses income from two years prior, a conversion in 2024 could affect your 2026 Medicare premiums. This is one reason the size and timing of conversions are worth thinking through carefully.

Can I appeal an IRMAA determination?

Yes. If your income has changed significantly due to a qualifying life-changing event (such as retirement, death of a spouse, divorce, or loss of pension income), you can request a reconsideration using Form SSA-44. Social Security can then use more recent income information to set your premium.

Do Roth withdrawals count toward IRMAA?

Generally, no. Qualified Roth IRA withdrawals are not included in your modified adjusted gross income, which means they do not count toward IRMAA. This is one of the reasons Roth accounts can be useful for managing Medicare costs in retirement.