IRMAA Surcharge Calculator
Enter your filing status and your MAGI. You'll see your 2026 Medicare surcharge in dollars, exactly how far you sit from the next cliff, and what a planned Roth conversion would do to both.
One dollar past $274,000 costs$3,472.80more for the year, household — the whole step, charged on every month.
The cliff, and what crossing it costs
IRMAA is a step, not a rate. What matters is the distance between your MAGI and the next threshold — and the size of the step waiting on the other side.
How much room you have left
Headroom is the extra MAGI you can recognise and still stay in tier 2. One dollar beyond it buys the entire next step.
Room before the next step
The marginal cost of one dollar
What the conversion does to your premiums
A Roth conversion of $100,000 is ordinary income, so it lands in MAGI in full — and shows up in your Medicare premiums two years later.
Tier 2
Tier 4
Added cost, one year
The two-year lookback: this year's MAGI sets your premiums two years from now. Your 2026 income — including any conversion you do between now and 31 December — determines your 2028 Part B and Part D premiums. The 2026 premiums you are paying today came from your 2024 return, which is closed. CMS has not announced the 2027 brackets, let alone 2028, so this tool applies the confirmed 2026 tiers as the best available basis. Thresholds normally drift up with inflation while the surcharge amounts track Part B costs.
How this works
MAGI for IRMAA is unusually simple: adjusted gross income plus tax-exempt interest. Nothing else is added and nothing is subtracted. Municipal bond interest counts against you even though it is not taxable. Qualified Roth withdrawals, the return of basis from a taxable account, HSA distributions for qualified expenses, and qualified charitable distributions never enter AGI in the first place, so they never appear in this test. Items that do count and are easy to forget: capital gains, the taxable portion of Social Security, RMDs, pension and annuity income, rental income, and Roth conversions.
The thresholds are cliffs, not slopes. This is not a marginal rate applied to the excess. Cross a threshold by a single dollar and you pay the entire step, every month, for the whole premium year — no phase-in, no proration. That is why the useful planning question is "how far am I from the line?" rather than "what is my tax bracket?". The corollary: if you are crossing a threshold anyway, cross it decisively, because income up to the next threshold is then surcharge-free.
The bill arrives two years late. Social Security uses the most recent federal return the IRS has passed to it, which in practice is the return from two years prior. Your 2026 premiums came off your 2024 return; a conversion you do in 2026 surfaces in your 2028 premiums, long after it feels like settled history. The 2027 brackets have not been announced as of July 2026 — CMS publishes each year's figures in the autumn of the preceding year, so they are expected around late October or November 2026. This calculator therefore models the confirmed 2026 tiers and makes no claim about later years.
What the tool does and doesn't do. It applies the 2026 tiers to a MAGI figure you supply and reports the surcharge per enrolled person, plus a household total when both spouses are enrolled. The Part D figure is the surcharge only — it sits on top of whatever your drug plan charges. The $283 Part B deductible is not income-related and is excluded. The tool does not compute your MAGI for you, model Social Security taxation or the 3.8% net investment income tax, or account for the small number of beneficiaries whose Part B premium is limited by the hold-harmless provision.
The 2026 IRMAA brackets
CMS released the 2026 figures on 14 November 2025. The standard Part B premium is $202.90 a month, up from $185.00, with an annual Part B deductible of $283. The surcharges below sit on top of that standard premium for Part B, and on top of your plan's premium for Part D. They are based on 2024 MAGI.
| MAGI — single / HoH | MAGI — married filing jointly | Part B surcharge | Part D surcharge | Total Part B premium |
|---|---|---|---|---|
| $109,000 or less | $218,000 or less | $0.00 | $0.00 | $202.90 |
| Over $109,000 to $137,000 | Over $218,000 to $274,000 | $81.20 | $14.50 | $284.10 |
| Over $137,000 to $171,000 | Over $274,000 to $342,000 | $202.90 | $37.50 | $405.80 |
| Over $171,000 to $205,000 | Over $342,000 to $410,000 | $324.60 | $60.40 | $527.50 |
| Over $205,000 to under $500,000 | Over $410,000 to under $750,000 | $446.30 | $83.30 | $649.20 |
| $500,000 or more | $750,000 or more | $487.00 | $91.00 | $689.90 |
Married filing separately is a compressed scale, and it is the unusual case. If you lived with your spouse at any point in the tax year but filed separately, there are only three bands: no surcharge at or below $109,000, a jump straight to $446.30 plus $83.30 above that, and the top step of $487.00 plus $91.00 at $394,000 and above. The middle steps do not exist, so the first threshold is the whole game. Most couples who file separately do so for a specific legal or student-loan reason; if IRMAA is the binding constraint, the filing decision itself is worth revisiting with your CPA.
For the full picture — what counts toward MAGI, the tactics that keep you under a line, and what is and isn't known about 2027 — see how to avoid IRMAA. If a life-changing event has already cut your income, the remedy is an appeal on Form SSA-44.
Frequently asked questions
Where to take this next
The surcharge is one line in a bigger decision. These are the pieces it connects to.
Roth conversion tax calculator
Model a conversion across a full retirement — four paths, the tax on each, and what's left at plan-end. The IRMAA cost you just priced is one year of it.
Full calculator →How to avoid IRMAA
What counts toward MAGI, what doesn't, the tactics ranked by how much they move the needle, and what is genuinely known about 2027.
Read the guide →Appealing IRMAA with Form SSA-44
If a life-changing event has already cut your income, Social Security will use the current figure instead. The form, line by line.
See the process →Retirement withdrawals & taxes
The withdrawal-order framework these tactics sit inside — which account to draw from, in which year, and why the sequence changes the tax bill.
Read the pillar →QCD rules for 2026
The cleanest lever available after 70½: up to $111,000 per person satisfies an RMD while staying out of AGI entirely — so it reduces the IRMAA test directly.
See the rules →All calculators
Every tool on the site in one place, from conversion modelling to the surcharge and RMD questions that sit around it.
Calculator hub →