What Is Medicare IRMAA? Why Some People Pay More for Part B and Part D
IRMAA is based on your income from two tax years ago, not your income today.
Key takeaways
- IRMAA (Income-Related Monthly Adjustment Amount) is a surcharge added to standard Part B and Part D premiums for higher-income enrollees.
- For 2026, IRMAA applies to single filers with income above $109,000 and joint filers above $218,000, based on income reported two years earlier (2024 for 2026 premiums).
- The 2026 surcharge is applied across five income brackets, with total monthly Part B premiums ranging from $284.10 to $689.90 for affected enrollees, and Part D surcharges ranging from $14.50 to $91.00.
- A one-time income drop from a specific, recognized life event (like retirement) can qualify you to request a reassessment rather than waiting two years for it to catch up.
If your Medicare Part B or Part D premium is noticeably higher than the standard amount you've seen quoted, IRMAA is very likely the reason — an income-based surcharge that a meaningful share of Medicare enrollees don't realize applies to them until they see it on their own bill.
What IRMAA actually is
The Income-Related Monthly Adjustment Amount is an additional charge added on top of the standard Part B premium (and, separately, the Part D premium) for enrollees whose income is above certain thresholds. It isn't a penalty for anything you did — it's simply an income-based pricing structure applied automatically based on tax data the Social Security Administration already has.
The actual 2026 numbers
For 2026, the IRMAA surcharge applies to single filers (and those married filing separately) with income above $109,000, and joint filers above $218,000. The brackets run on a sliding scale across five tiers, topping out at $500,000 for individual filers and $750,000 for joint filers. For affected enrollees, total monthly Part B premiums range from $284.10 to $689.90, and Part D surcharges range from $14.50 to $91.00 — both layered on top of, not instead of, the standard premium.
2026 Part B IRMAA brackets (illustrative — five total tiers apply)
| 2026 income (single filer) | 2026 income (joint filers) | Approx. total monthly Part B premium |
|---|---|---|
| $109,000 or less | $218,000 or less | Standard premium — no surcharge |
| Above $109,000, up to the next bracket | Above $218,000, up to the next bracket | Higher of $284.10, scaling up through the brackets |
| Up to $500,000 (top bracket) | Up to $750,000 (top bracket) | Up to $689.90 |
The two-year lookback that confuses people
IRMAA for a given year is based on your modified adjusted gross income from your tax return two years earlier — meaning your 2026 premium reflects your 2024 income, not your income right now. This lag is the single most common source of confusion: someone whose income has since dropped, for instance after retiring, can still be paying an IRMAA surcharge based on their higher pre-retirement income until the lookback catches up.
- IRMAA applies in income brackets — as your income rises past each threshold, the surcharge increases in a step, not as one flat additional amount for everyone above the base threshold.
- It applies separately to Part B and Part D, meaning higher-income enrollees can see an IRMAA surcharge on both premiums, not just one.
- Both the income thresholds and surcharge amounts are set and adjusted by CMS and Social Security annually and can change from year to year.
The exception: requesting a reassessment
If your income has dropped since the two-year-old tax return currently being used because of a specific, recognized life-changing event — retirement, a reduction in work hours, the death of a spouse, among others recognized by Social Security — you can request that your IRMAA be reassessed using more current income information rather than waiting for the standard two-year lookback to catch up on its own. This requires proactively filing a request; it doesn't happen automatically.
Understanding and managing your IRMAA exposure
- Check your IRMAA determination notice for the specific income bracket and tax year it's based on.
- If your income has genuinely dropped due to a recognized life event, file a reassessment request with Social Security rather than waiting two years.
- Understand IRMAA applies separately to Part B and Part D — check both if you're reviewing your total premium.
- Don't assume last year's IRMAA bracket carries forward — thresholds and amounts are adjusted annually.
- If you're planning a major income event (a Roth conversion, a large capital gain), factor in the two-year IRMAA lookback before assuming it won't affect your premiums.
If you receive an IRMAA determination notice that no longer reflects your actual income because of retirement or another qualifying life event, don't just accept the higher premium — file a reassessment request with Social Security. It requires action on your part; it won't happen automatically.
Frequently asked questions
Will my rate go back down if my income drops?
It can, but only automatically once the two-year lookback catches up, or sooner if you proactively file a reassessment request following a qualifying life event like retirement.
Does IRMAA apply to both spouses if we file jointly?
IRMAA is assessed per Medicare enrollee based on the household's reported income and filing status — if both spouses are enrolled in Medicare and the household income exceeds the joint threshold, both could be subject to IRMAA.
Is IRMAA the same as the late enrollment penalty?
No — they're entirely different mechanics. IRMAA is an income-based surcharge unrelated to enrollment timing; the late enrollment penalty applies specifically for not enrolling on time. It's possible to be subject to one, both, or neither.
How do I know if I'm subject to IRMAA?
You'll receive a determination notice from Social Security stating your income bracket and the resulting premium if you're subject to IRMAA. If you're unsure, contact Social Security directly to confirm your specific status.
Sources
Facts and figures in this guide that come from an outside authority are backed by the sources below. Pricing, program rules, and eligibility details change — always confirm current specifics with the source directly or a licensed professional before acting.
- Income related monthly adjustment amount (IRMAA) for 2026 Medicare Part B & Part D PremiumsHumana · Updated 2026 · Accessed 2026-07-20
- Medicare Premiums 2026: IRMAA Brackets and Surcharges for Parts B and DKiplinger · Updated 2026 · Accessed 2026-07-20
- 2026 2027 2028 Medicare IRMAA Premium MAGI BracketsThe Finance Buff · Updated 2026 · Accessed 2026-07-20
- IRMAA Brackets 2026: What They Are and How They WorkNerdWallet · Updated 2026 · Accessed 2026-07-20
- Medicare & YouCenters for Medicare & Medicaid Services (CMS) / Medicare.gov · Updated 2026 · Accessed 2026-07-20
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