Some Medicare beneficiaries discover their Part B premium is more than double the standard amount, without having switched plans or made any mistake. That is IRMAA: an income-based surcharge added to your Part B and Part D premiums when your tax return from two years earlier exceeded certain thresholds. This guide explains the 2026 brackets, how it's calculated, what to do if your income dropped, and how an agent can help you plan ahead.
What IRMAA is, and why there's a two-year lag
IRMAA stands for Income-Related Monthly Adjustment Amount: an adjustment to your premium based on your income. Social Security uses your tax return from two years earlier because it's the most recent information the IRS has processed; your 2026 premiums are calculated using your 2024 return, not your current income.
This lag is why many people are caught off guard: they pay a high surcharge in a year when they've already retired, because the letter reflects an earlier year when they were still working full time. It also means a decision you make today — like a large Roth conversion — won't affect your Medicare premium until two years from now.
The 2026 IRMAA income brackets for Part B
The standard Part B premium in 2026 is $202.90 per month. If your 2024 MAGI exceeded certain thresholds, you pay an additional surcharge, calculated in five tiers depending on your filing status:
| 2024 MAGI (Single) | 2024 MAGI (Married filing jointly) | Total Part B premium |
|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 |
| $109,001 – $137,000 | $218,001 – $274,000 | $284.10 |
| $137,001 – $171,000 | $274,001 – $342,000 | $405.80 |
| $171,001 – $205,000 | $342,001 – $410,000 | $527.50 |
| $205,001 – $499,999 | $410,001 – $749,999 | $649.20 |
| $500,000 or more | $750,000 or more | $689.90 |
If you file as married filing separately, the structure compresses sharply: you pay $202.90 up to $109,000, jump to $649.20 between $109,001 and $390,999, and $689.90 from $391,000 up, without the intermediate tiers for single and joint filers.
The 2026 Part D brackets
The Part D IRMAA surcharge uses the same thresholds as Part B, but it's added to your drug plan and paid to Social Security, not your insurer. It ranges from $14.50 a month at the first tier up to $91.00 at the top tier, on top of the premium you already pay for your Advantage plan with drug coverage or standalone Part D plan.
Availability, cost, benefits, and eligibility vary by person, product, contract, and insurance company, as well as by your service area. Guarantees are subject to the claims-paying ability of the issuing insurance company. Karla Arámburo is not affiliated with or endorsed by Medicare or the federal government.
The cliff effect: why one extra dollar matters so much
Unlike income tax brackets, IRMAA is not gradual: if your 2024 MAGI landed one dollar above a threshold, you pay that entire tier's surcharge, not just on the amount over the line. A single filer with $137,001 in income pays exactly the same surcharge as someone with $170,000, while someone with $136,999 pays an entire bracket less.
This is also why an occasional property sale or a large required minimum distribution can push you into a higher bracket even if your usual income is modest. Reviewing your projected MAGI before the calendar year ends, while you can still adjust something, is usually more useful than discovering it later in the Social Security letter.
What to do if your income dropped: Form SSA-44
If your income dropped due to one of eight life events Social Security recognizes as qualifying — marriage, divorce or annulment, the death of your spouse, retirement or reduced work hours, an involuntary loss of a pension income source, an employer settlement payment, or the sale of a farming or fishing business — you can file Form SSA-44 asking them to use more recent income.
The form is filed with evidence of the event — a retirement letter, a death certificate, a divorce decree — and a reasonable estimate of your current income. There's no fixed deadline: you can file as soon as the event occurs, at your local Social Security office or by mail, without waiting for the IRMAA determination letter first.
It's important to note what doesn't qualify: a voluntary Roth conversion, a required minimum distribution, or a capital gain from a personal decision are not recognized events, no matter how much they raised your income. For those situations, the only real tool is planning ahead.
Planning ahead: Roth conversions, withdrawals, and annuities
Because IRMAA is calculated with a two-year lag and works like a cliff, the best defense is usually planning the timing of your income before it happens. Gradual Roth conversions before you enroll in Medicare, or in low-income years, can reduce future required minimum distributions without pushing you into a higher bracket.
When you begin withdrawing from a fixed annuity matters too: structuring it to pay out after confirming your IRMAA tier, rather than alongside other large income, prevents two sources from stacking in the same tax year. We cover this in our fixed annuities guide to see whether it makes sense in your case.
Rolling over a 401(k) or IRA can also carry IRMAA implications if it triggers a taxable distribution in the wrong year. Before moving those funds, review our 401(k) rollover checklist and coordinate the withdrawal with your overall plan, which we cover in our retirement income planning guide.
Where an insurance agent fits into this conversation
An agent doesn't prepare tax returns or replace an accountant or financial planner, but they can help you see how the timing of a fixed annuity or a rollover interacts with the IRMAA brackets. For the base premium the surcharge is calculated on top of, see our Medicare Part B guide.
Karla Arámburo is a bilingual, California-licensed insurance agent serving Southern California residents, and reviewing how IRMAA affects your specific situation costs nothing and comes with no pressure to enroll. You can call or text (619) 321-8733 to schedule a no-cost conversation. This page is general education, not tax advice or an enrollment recommendation.
Frequently asked questions
What exactly is IRMAA?
IRMAA is a surcharge Medicare adds to Part B and to your Part D plan when your income exceeds certain thresholds. It is not a fine or a late enrollment penalty — it's a higher premium for higher income, recalculated every year by Social Security.
Which tax return does Social Security use to calculate my 2026 IRMAA?
Your 2026 IRMAA surcharge is based on your 2024 tax return, the most recent one the IRS had processed when this year's brackets were set. That is why a 2026 retirement or property sale won't affect your premium for two more years, unless you request a reconsideration.
Can one extra dollar of income really cost me thousands of dollars a year?
Yes: IRMAA works like a cliff, not a gradual ladder. One dollar above a threshold triggers that tier's full surcharge for the whole year. Crossing the first tier as a single filer can add over a thousand dollars a year between Part B and Part D.
What counts as income for IRMAA, and what doesn't?
It counts your adjusted gross income plus tax-exempt interest, like municipal bonds: pensions, traditional 401(k) or IRA withdrawals, capital gains, Roth conversions, and the taxable portion of Social Security. It does not count qualified Roth withdrawals or qualified HSA withdrawals, which makes both valuable planning tools.
My spouse passed away and now I file as single. Why did my Medicare go up so much?
Because the threshold for single filers is roughly half the threshold for married couples, but household income rarely drops by half when a spouse dies: the pension, Social Security, and retirement withdrawals often continue almost unchanged. It's a common reason for an unexpected IRMAA notice, and it often qualifies for a reconsideration using Form SSA-44.
How do I appeal my IRMAA with Form SSA-44?
You file Form SSA-44 with Social Security along with evidence of the qualifying life event and your more recent income. You can submit it at your local office or by mail, with no strict deadline — as soon as the qualifying event happens.
Which life events qualify to lower my IRMAA?
Social Security recognizes eight events: marriage, divorce or annulment, the death of a spouse, retirement or reduced work hours, involuntary loss of a pension, an employer settlement payment, and the sale of a farming or fishing business. A voluntary Roth conversion or a required minimum distribution does not qualify.
Can an insurance agent help me avoid IRMAA in future years?
An agent cannot change your tax return or replace an accountant or financial planner, but they can help you understand how your retirement decisions — such as when to withdraw from a fixed annuity — interact with the IRMAA brackets, and coordinate with you and your accountant before a major decision.