Dollar Almanac

Medicare IRMAA Bracket Calculator

Updated

Higher earners pay a surcharge on Medicare Part B and Part D. It is decided by a tax return from two years ago, and it is a cliff rather than a phase-in.

Your Medicare surcharge is set by your modified adjusted gross income from two years earlier, and crossing a threshold by a single dollar raises your premium for the whole year rather than just on the income above it.

Adjusted gross income plus tax-exempt interest, from the return two years back. Not this year's income.

Filing status on that return

Surcharge for the year

$1,148.40

Part B surcharge, monthly
$81.20
Part D surcharge, monthly
$14.50
Part B premium including the surcharge
$284.10
Income before the next threshold
$27,999.00
Tier
2 of 6
Crossing the next threshold costs
$1,736.40 a year

info: These premiums are set by your 2024 income

Medicare uses the return from two years back, because it is the most recent one the IRS has when premiums are set. A drop in income since then does not change the premium on its own. If the drop came from a life-changing event such as stopping work, form SSA-44 is how you ask for it to be reconsidered.

info: The Part D figure is an addition, not a premium

It is added to whatever your drug plan charges. Plan premiums vary and are not set by Medicare, so the total cannot be shown here.

What this assumes

Assumption set CMS 2026

Income year
2024 MAGI, for 2026 premiums
Filing status
SINGLE
Table read
Individual
People enrolled
One
Premiums and thresholds
CMS fact sheet, 2026 Medicare Parts A & B Premiums and Deductibles
Filing-status rules
SSA POMS HI 01101.020
MAGI and lookback
42 U.S.C. §1395r(i)

How this works

Medicare Part B and Part D have a standard cost. Above an income threshold, both carry an additional charge, the income-related monthly adjustment amount. It is per person, per month, and it is decided by one number: your modified adjusted gross income from two years before the premium year.

Two features make it worth a calculator rather than a table.

  • It is a cliff. Income tax raises the rate on the dollars above a threshold. This raises the charge on the whole year. One extra dollar can cost over a thousand.
  • The income is old. By the time the premium arrives, the return that set it is two years behind you, and nothing about filing that return said anything about Medicare.

Worked example

Someone single, enrolled in Medicare, with modified adjusted gross income of $109,000.00 in 2024. That is exactly the first threshold, and it is inclusive, so they are in tier 1: no surcharge on either part.

One dollar more, $109,001.00, and they are in tier 2. Part B gains $81.20 a month and Part D gains $14.50, so the Part B premium goes from $202.90 to $284.10.

Over a year that is $1,148.40 for one dollar of income. If a spouse were also enrolled, the household would pay it twice.

Which table you read

Medicare publishes three tables against five filing statuses, so three statuses share one. Single, head of household and qualifying surviving spouse all use the individual table. Married filing jointly has its own. Married filing separately has a third, but only for couples who lived together at some point in the year; those who lived apart for the whole year use the individual one.

That last distinction is worth care. Social Security assumes a separately-filing couple lived together and applies the higher table until the beneficiary shows otherwise, so the answer to one yes-or-no question is the difference between two very different bills at the same income.

What this does not tell you

It does not show a total Part D premium, because Medicare does not set one. The Part D figure here is the surcharge, added to whatever your plan charges.

It takes adjusted gross income and tax-exempt interest as the inputs to modified adjusted gross income. The statute also adds back four exclusions, for savings bond interest used for education, foreign earned income and housing, and income from Guam, American Samoa, the Northern Mariana Islands and Puerto Rico. Those are deliberately out of scope rather than silently ignored; anyone with one will need to add it to the figure they enter.

It also does not cover the immunosuppressive-drug-only Part B benefit, which has its own tables, or the appeal process beyond naming it. How we compute things sets out what these tools do and do not do.

Sources

References used to explain this page. Listing a publisher is not a claim that they endorse it.

Figures are transcribed from these documents directly. Where a value has not been verified against its source, this page shows no number rather than an estimate.

Questions

Why is my premium based on income from two years ago?
Because premiums for a year have to be set before the year begins, and the most recent return the IRS has finished processing by then is the one from two years earlier. It is fixed in statute rather than left to administration. The practical effect is that the surcharge arrives long after the income that caused it, which is why retirement is the most common time to meet it.
What counts as income for this?
Adjusted gross income plus tax-exempt interest. Both parts matter: municipal bond interest is exempt from income tax and still counts here, which surprises people who hold munis for exactly that exemption. It is AGI rather than taxable income, so it is measured before the standard or itemized deduction.
Does head of household have its own thresholds?
No. Medicare publishes three tables, not five. Single, head of household and qualifying surviving spouse all read the same one. The federal income tax brackets do give head of household its own table, which is why this catches people out.
I file separately from my spouse. Which table applies?
It depends on whether you lived together at any point in the year. If you did, there is a separate three-tier table that jumps straight to a much higher surcharge just above the base threshold. If you lived apart for the entire year, you use the individual table. Social Security applies the higher one until you establish otherwise, either with the indicator on your Form 1040 or by attesting.
Is the surcharge per person or per couple?
Per person. A married couple is tested once against their combined income, and then each spouse who is enrolled in Medicare pays the surcharge separately. A couple who are both enrolled pay it twice, which is the figure this page shows when you say both are enrolled.
My income has dropped since then. Can I do anything?
If the fall was caused by a life-changing event, yes. Form SSA-44 asks for the determination to be made on more recent income, and the qualifying events are specific: marriage, divorce or annulment, the death of a spouse, work stoppage, work reduction, loss of income-producing property, loss of pension income, or an employer settlement payment. Retirement counts as work stoppage. A fall in income with no qualifying event behind it does not qualify, however large.
Why does the calculator not show my total Part D premium?
Because Medicare does not set it. The Part D figure here is the surcharge alone, which is added to whatever your drug plan charges. Plan premiums vary by plan and by area, so a total would require a number this page does not have and should not guess.
Do the thresholds change each year?
Most of them do. The lower thresholds are adjusted annually, but the top ones, $500,000 for an individual and $750,000 for a couple, are fixed in statute and are not adjusted for inflation until 2028. So the top tier captures more people each year while everything below it moves.

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