Are you prepared for “Aunt IRMAA” to drop by?Â
IRMAA isn’t a person, of course—it’s the acronym for Medicare’s “income-related monthly adjustment amount.” But as a Certified Public Accountant (CPA), when you talk about something long enough, you tend to assign it a cutesy phrase, and IRMAA was just lucky enough to be invited to the family barbecue.
My quirks aside, IRMAA is a surcharge that high-income earners sometimes pay for Medicare Parts B and D. And even though most Americans aren’t subject to this surcharge, you should at least understand it in case you ever need to pay it—or in case you ever want to avoid having to pay it.
Read on, and I’ll briefly explain how IRMAA works, then go over the income thresholds for this year.
How Does IRMAA Work?
Medicare itself doesn’t have an income limit. If you want Part B (medical insurance) and/or Part D (optional prescription drug coverage), no amount of earnings can disqualify you from signing up—as long as you can pay the premiums, of course.Â
The government helps out by covering about 75% of Part B’s premium; although private insurers issue Part D plans and largely determine their prices, the government heavily subsidizes this program, too.
However, if you’re part of a high-income household that surpasses an annual threshold, you might be subject to an income-related monthly adjustment amount (read: a visit from Aunt IRMAA).
But it won’t be a surprise visit. If you’re going to owe IRMAA on Part B and/or (if applicable) Part D premiums, the Social Security Administration will inform you via an Initial Determination Notice.
If you receive Social Security benefits, your Part B premium is deducted from your Social Security check, regardless of whether or not you’re subject to the IRMAA surcharge. Part D premiums are sent to your plan, but if you need to pay the IRMAA surcharge, the extra amount is paid to Medicare.
What Are the 2026 IRMAA Surcharge Thresholds?
IRMAA is based on people’s tax returns from two years prior. For example: Your 2025 tax return is used to determine whether you’re subject to an IRMAA on your 2027 Medicare premiums. And your IRMAA applicability and amount is recalculated every year.Â
The modified adjusted gross income (MAGI) used to calculate IRMAA is specific to MAGI. It’s different from the MAGI used for non-healthcare purposes and the MAGI used to determine premium tax credits and Medicaid/CHIP eligibility.
To calculate IRMAA MAGI, you take your adjusted gross income (Form 1040, Line 11) and add any tax-exempt interest income (Form 1040, Line 2a). Standard or itemized deductions reduce your taxable income but not your IRMAA MAGI. There are a few other wrinkles, including that federal-tax-free-income such as interest from munibonds counts toward the IRMAA threshold, and Social Security income is included, but only the taxable portion, not the total gross amount.
The IRMAA income thresholds are the same for Part B and Part D, but the adjustment amounts are different.
Related: 12 Costs ‘Original Medicare’ Doesn’t Cover
Single, head of household, qualifying widow(er) with dependent child, married filing separately (and did not live with your spouse during the tax year)
For 2026, the IRMAA surcharge kicks in once you reach at least $109,000.01; the lowest adjustment amount is $81.20 for Part B and $14.50 for Part D.
The adjustment amount steps up in tiers as your MAGI increases. The MAGI threshold maxes out above $499,999.99, at which point you’ll face the maximum adjustments of $487.00 for Part B and $91.00 for Part D.
Married filing jointly
The IRMAA surcharge for 2026 kicks in once your MAGI reaches $218,000.01. The minimum adjustments are $81.20 for Part B and $14.50 for Part D, and increase in tiers until you earn more than $749,999.99, at which point your IRMAAs would be $487.00 for Part B and $91.00 for Part D.
Married filing separately (and did live with your spouse during at least part of the tax year)
Anyone married filing separately who lived with a spouse during part of the tax year pays a $446.30 Part B surcharge and $83.30 Part D surcharge if their MAGI falls between $109,000.01 and $390,999.99. For MAGIs above $390,999.99, the adjustment is $487.00 for Part B and $91.00 for Part D.
This table breaks down all of the IRMAA tiers:
| MAGI | Part B IRMAA | Part D IRMAA |
|---|---|---|
| Single, head of household, qualifying widow(er) with dependent child, married filing separate (and did not live with your spouse during the tax year) | ||
| $109,000.01-$137,000.00 | $81.20 | $14.50 |
| $137,000.01-$171,000.00 | $202.90 | $37.50 |
| $171,000.01-$205,000.00 | $324.60 | $60.40 |
| $205,000.01-$499,999.99 | $446.30 | $83.30 |
| > $499,999.99 | $487.00 | $91.00 |
| Married filing jointly | ||
| $218,000.01-$274,000.00 | $81.20 | $14.50 |
| $274,000.01-$342,000.00 | $202.90 | $37.50 |
| $342,000.01-$410,000.00 | $324.60 | $60.40 |
| $410,000.01-$749,999.99 | $446.30 | $83.30 |
| > $749,999.99 | $487.00 | $91.00 |
| Married filing separately (and did live with your spouse during part of the year) | ||
| $109,000.01-$390,999.99 | $446.30 | $83.30 |
| > $390,999.99 | $487.00 | $91.00 |
Related: Average Monthly Social Security Benefits by Age
Subject to IRMAA and Don’t Think You Should Be?
Subject to IRMAA and don’t think you should be? You can appeal your IRMAA determination. People who have had a life-changing event, such as a divorce, can also file for a redetermination using Form SSA-44.Â
One last note: The “hold harmless” provision that doesn’t allow Medicare Part B premiums to increase by more than the annual Social Security cost-of-living adjustment (COLA) for the year does not apply to people who pay the IRMAA surcharge for Part B.
Related: 2027 COLA: How Much Will Social Security Checks Grow?
