Medicare IRMAA (Income-Related Monthly Adjustment Amount) is a surcharge added to your standard Medicare Part B and Part D premiums if your income exceeds a certain threshold. For 2026, that threshold is $109,000 for individual filers and $218,000 for married couples filing jointly. If your income falls below those numbers, you pay only the standard premium and IRMAA doesn’t apply to you at all.
The surcharge exists because Medicare is partially funded by taxpayers, and higher earners are required to cover a larger share of their own costs. It’s not a one-time fee. It’s an additional monthly charge on top of what you already pay for Parts B and D, and it can add hundreds of dollars per month depending on your income.
How IRMAA Is Calculated
Social Security determines your IRMAA using your modified adjusted gross income (MAGI) from two years prior. So your 2026 surcharge is based on your 2024 tax return, and your 2025 surcharge was based on your 2023 return. MAGI includes your adjusted gross income plus any tax-exempt interest income, such as earnings from municipal bonds.
This two-year lookback catches many people off guard. If you had an unusually high-income year, perhaps from selling a home, cashing out investments, or converting a traditional IRA to a Roth, you could trigger IRMAA two years later even if your current income is much lower. The system doesn’t automatically account for one-time spikes.
2026 IRMAA Brackets for Part B
The standard Part B premium for 2026 is $202.90 per month. If your 2024 income was higher than the base threshold, your total monthly Part B premium rises through five tiers:
- $109,001 to $137,000 (individual) / $218,001 to $274,000 (joint): $284.10 per month
- $137,001 to $171,000 (individual) / $274,001 to $342,000 (joint): $405.80 per month
- $171,001 to $205,000 (individual) / $342,001 to $410,000 (joint): $527.50 per month
- $205,001 to $499,999 (individual) / $410,001 to $749,999 (joint): $649.20 per month
- $500,000 or more (individual) / $750,000 or more (joint): $689.90 per month
At the highest tier, you’re paying more than three times what someone below the threshold pays. Over a full year, that top bracket adds roughly $5,844 in extra Part B costs alone.
IRMAA Also Applies to Part D
Part D (prescription drug coverage) has its own separate IRMAA surcharge using the same income brackets. For 2025, those surcharges range from $13.70 per month at the lowest affected tier to $85.80 per month at the highest. This is added on top of whatever your Part D plan already charges.
The Part D surcharge is smaller than Part B’s, but combined, the two can significantly increase your total Medicare costs. Someone in the second-highest bracket for 2025 would pay an extra $406.90 for Part B plus $78.60 for Part D, totaling nearly $486 in monthly surcharges before their actual plan premiums.
Married Filing Separately: A Penalty Bracket
If you’re married but file a separate tax return, the bracket structure is much less favorable. For 2026, there are only two tiers instead of five. Income above $109,000 up to $391,000 jumps straight to the $649.20 monthly Part B premium, and $391,000 or above puts you at the maximum $689.90. There’s no gradual middle ground. This means married-filing-separately filers can face significantly higher IRMAA charges at the same income level compared to joint filers.
How You Pay IRMAA
If you collect Social Security benefits, both the Part B and Part D IRMAA surcharges are automatically deducted from your monthly Social Security check. You’ll see the deduction on your Social Security statement. If you don’t receive Social Security benefits yet, Medicare bills you directly for the surcharge.
Social Security sends you an initial determination letter (called an IRMAA notice) each year, typically in the fall, letting you know whether you owe a surcharge and how much. This letter also explains your appeal rights.
Life-Changing Events That Can Lower Your IRMAA
Because IRMAA uses two-year-old tax data, it can be inaccurate if your financial situation has changed. Social Security recognizes several qualifying “life-changing events” that allow you to request a new determination based on your current or more recent income. You do this by filing Form SSA-44, which you can submit to your local Social Security office.
The qualifying events are:
- Marriage
- Divorce or annulment
- Death of a spouse
- Work stoppage or reduction in hours (for you or your spouse)
- Loss of income-producing property (due to disaster, arson, fraud, or theft, not a voluntary sale)
- Loss of pension income (from an employer plan termination or reorganization)
- Employer settlement payment (from a bankrupt or reorganizing employer)
Retirement is one of the most common triggers. If you were still working when you filed the tax return Social Security is using, but you’ve since retired and your income has dropped substantially, a work stoppage claim through Form SSA-44 can get your IRMAA reduced or eliminated. You’ll need to provide evidence of the event and an estimate of your current-year income.
What Counts Toward the Income Threshold
MAGI for IRMAA purposes is your adjusted gross income plus tax-exempt interest. That means it includes wages, self-employment income, pensions, rental income, capital gains, IRA distributions, and interest from tax-free bonds. Social Security benefits that are taxable also count. Roth IRA withdrawals generally do not count because they aren’t included in adjusted gross income, which is one reason Roth conversions (done strategically in lower-income years) are a common planning tool for managing IRMAA.
Keep in mind that even a single dollar over a threshold moves you into the next bracket. There’s no phase-in or gradual increase within a tier. If you file individually and your MAGI is $109,001, your 2026 Part B premium jumps from $202.90 to $284.10, an extra $974 over the year for one dollar of income.