The standard Medicare Part B premium in 2026 is $202.90 a month, and for most people that is what comes out of the Social Security payment. Above certain income levels it is not, and the extra amount — the income-related monthly adjustment amount, or IRMAA — is large enough to be worth planning around two years in advance.
That two-year gap is the whole problem. The letter arrives in the autumn of 2025 telling you what you will pay in 2026, based on a tax return you filed in 2025 for the year 2024. By then the income that caused it is history, and nothing you do in 2026 changes it.
The lookback, and why the surprise is structural
Social Security determines your 2026 IRMAA from the MAGI on your 2024 tax return. If that return is not available, the 2023 return is used instead.
So the sequence is: earn in 2024, file in 2025, pay in 2026.
This matters most for people who retired in between. Someone who worked a full year in 2024, retired in 2025, and is living on a pension in 2026 is charged on the working year's income. The surcharge describes a financial life they no longer have. That is not an error — it is how the rule is built — and it is exactly the case the appeal below exists for.
It also matters for one-off events. A Roth conversion, a house sale, a large capital gain or an inherited IRA distribution in 2024 all raise MAGI, and all of them show up as a Medicare bill two years later. If you are near a threshold and planning any of those, the contribution and account rules are only half the picture; the Medicare consequence is the other half.
The 2026 Part B brackets
Individual filers:
| MAGI (2024 return) | Adjustment | Total monthly premium |
|---|---|---|
| $109,000 or less | $0.00 | $202.90 |
| Above $109,000 to $137,000 | $81.20 | $284.10 |
| Above $137,000 to $171,000 | $202.90 | $405.80 |
| Above $171,000 to $205,000 | $324.60 | $527.50 |
| Above $205,000 and below $500,000 | $446.30 | $649.20 |
| $500,000 or more | $487.00 | $689.90 |
Married filing jointly:
| MAGI (2024 return) | Adjustment | Total monthly premium |
|---|---|---|
| $218,000 or less | $0.00 | $202.90 |
| Above $218,000 to $274,000 | $81.20 | $284.10 |
| Above $274,000 to $342,000 | $202.90 | $405.80 |
| Above $342,000 to $410,000 | $324.60 | $527.50 |
| Above $410,000 and below $750,000 | $446.30 | $649.20 |
| $750,000 or more | $487.00 | $689.90 |
Note that these are per person. A married couple both on Medicare, both above a threshold, each pay the adjustment.
Part D has its own surcharge, billed separately
The part people miss. IRMAA applies to Part D as well, and it is charged on top of whatever premium you agreed with your drug plan — billed separately, so it does not appear on the plan's own paperwork.
| MAGI (2024 return), individual | Joint | Part D adjustment |
|---|---|---|
| $109,000 or less | $218,000 or less | $0.00 |
| Above $109,000 to $137,000 | Above $218,000 to $274,000 | $14.50 |
| Above $137,000 to $171,000 | Above $274,000 to $342,000 | $37.50 |
| Above $171,000 to $205,000 | Above $342,000 to $410,000 | $60.40 |
| Above $205,000, below $500,000 | Above $410,000, below $750,000 | $83.30 |
| $500,000 or more | $750,000 or more | $91.00 |
The cliff, which is the part worth acting on
IRMAA does not phase in. Cross a threshold by any amount and the entire step applies.
At the first threshold that means $81.20 a month on Part B plus $14.50 on Part D — $95.70 a month, or $1,148.40 over the year, for one dollar of income.
The same arithmetic at the top: $487.00 plus $91.00 is $578.00 a month, or $6,936 a year above standard, for a single person.
This is the reason to know where the lines sit before December of the year in question rather than after. If your 2026 MAGI is going to land near $109,000, the difference between $108,900 and $109,100 is not two hundred dollars — it is two hundred dollars and a surcharge in 2028.
Married filing separately is treated differently
Worth stating on its own, because the schedule is unlike the others:
| MAGI (2024 return) | Part B adjustment | Part D adjustment |
|---|---|---|
| $109,000 or less | $0.00 | $0.00 |
| Above $109,000 and below $391,000 | $446.30 | $83.30 |
| $391,000 or more | $487.00 | $91.00 |
There is no gentle middle. A separate filer one dollar above $109,000 pays the $446.30 adjustment — the same amount a joint filer reaches only above $410,000. If you are considering filing separately for other reasons and either spouse is on Medicare, this belongs in the calculation.
Appealing: form SSA-44
Where a life-changing event has reduced your income since the tax year used, you can ask Social Security to base the determination on the newer figure instead. The form is SSA-44, and the qualifying events include:
- retirement, or a reduction in work hours
- the death of a spouse
- marriage or divorce
- loss of income-producing property
- loss or reduction of certain pension income
The event that goes unclaimed most often is the first one. Retiring is a life-changing event for this purpose, and a great many people who retire between the tax year and the premium year simply pay the surcharge because nobody told them there was a form.
A one-off Roth conversion or a capital gain is not a life-changing event. The list is specific, and a high-income year on its own does not qualify however unrepresentative it was.
What to actually check
- Which year is being used? For 2026 it is your 2024 return. Find that MAGI figure before assuming anything.
- Have you retired since then? If so, SSA-44 is likely worth filing, and it is not automatic.
- Are you within a few thousand dollars of a threshold this year? That is a planning question for December, not April.
- Did you count Part D? The full cost of a bracket is both adjustments, not just Part B.
- Are both spouses on Medicare? The adjustment applies to each of you.
For the standard premiums, deductibles and what Original Medicare does not cap, see the guide to Medicare costs in 2026. For how the cost-of-living adjustment interacts with the premium, see the 2026 Social Security figures.
This article explains the brackets. It is not advice on your return or your Medicare enrolment, and decisions about income timing near a threshold depend on your full tax position. A CPA or enrolled agent is the right person for that.
Sources
- CMS — 2026 Medicare Parts A & B Premiums and Deductibles (opens in a new tab)
- SSA — Form SSA-44, Medicare Income-Related Monthly Adjustment Amount, Life-Changing Event (opens in a new tab)
- SSA — Request to lower an Income-Related Monthly Adjustment Amount (opens in a new tab)
- SSA POMS HI 01101.020 — IRMAA sliding scale tables (opens in a new tab)
- Medicare.gov — Initial IRMAA determination notice (opens in a new tab)
This article is general information for a United States audience and reflects the 2026 Medicare figures published by CMS. It is not financial, tax or insurance advice. Thresholds and adjustment amounts change annually. Confirm against your own IRMAA determination notice and take advice from a qualified tax professional before acting on any of this. Last reviewed 13 September 2026.
