Medicare IRMAA explained: the income surcharge on a parent’s Part B and Part D
IRMAA is an amount added to a higher-income enrollee’s standard Part B premium and to the premium charged by the enrollee’s Part D plan. Social Security generally uses tax information from 2 years earlier, so the notice can reflect income that has since changed.
What is IRMAA?
IRMAA is an income-related monthly adjustment amount added on top of the standard Part B premium and on top of a plan’s Part D premium for higher-income enrollees.
The standard Part B premium is $202.90 per month in 2026, and the Part B annual deductible is $283. IRMAA does not replace either amount. It is the additional monthly amount described in the Social Security determination.
How does Social Security decide if a parent owes IRMAA?
For 2026, Social Security generally bases IRMAA on modified adjusted gross income from the 2024 federal tax return, or the 2023 return if 2024 information is not yet available.
This is the 2-year income lookback. No IRMAA applies at or below $109,000 for someone filing as single, head of household, or qualifying surviving spouse, or at or below $218,000 for someone married filing jointly. At or below those amounts, the 2026 Part B premium is the standard $202.90 per month and there is no Part D adjustment.
What are the 2026 IRMAA brackets?
Social Security’s 2026 sliding scale sets the total monthly Part B premium and the separate monthly Part D IRMAA amount for each income bracket.
| Single filer MAGI | Married filing jointly MAGI | Total monthly Part B premium | Part D IRMAA added per month |
|---|---|---|---|
| More than $109,000 through $137,000 | More than $218,000 through $274,000 | $284.10 | +$14.50 |
| More than $137,000 through $171,000 | More than $274,000 through $342,000 | $405.80 | +$37.50 |
| More than $171,000 through $205,000 | More than $342,000 through $410,000 | $527.50 | +$60.40 |
| More than $205,000 but less than $500,000 | More than $410,000 but less than $750,000 | $649.20 | +$83.30 |
| $500,000 or more | $750,000 or more | $689.90 | +$91.00 |
The Part D amount in the last column is added to whatever the parent’s own drug plan charges. It is not the plan’s premium.
Why doesn’t the 2027 amount appear yet?
The 2027 IRMAA brackets and standard Part B premium are not available as of this guide’s August 2026 publication date because SSA and CMS publish those figures in the fall.
CMS typically publishes the annual Medicare Parts A & B Premiums and Deductibles fact sheet in mid-November. The 2026 brackets above are the current cited reference while the mechanism remains the same: the determination uses the applicable year’s brackets and tax information from 2 years earlier. This guide will be updated when the 2027 figures are published.
What if a parent’s income dropped?
Social Security lets an enrollee ask it to use more recent income when income dropped because of a qualifying life-changing event, using form SSA-44.
SSA lists life-changing events that include:
- Work stoppage or retirement
- Marriage or divorce
- Death of a spouse
- Loss of pension income
Form SSA-44 and SSA’s Request to lower an IRMAA page explain the official process, the information requested, and how to submit the request. SSA decides whether the process applies and whether to use the more recent income information.
Where does this show up?
Social Security mails an IRMAA determination notice in the fall, while a parent’s own plan documents state the plan’s Part D premium.
The Social Security notice explains the income information and adjustment it used. Keeping that notice next to the plan’s Annual Notice of Change separates the government-set Part D adjustment from the drug plan’s own premium.
Sources
- SSA, Program Operations Manual System HI 01101.020, IRMAA sliding scale tables (the 2026 brackets, Part B premiums, and Part D adjustment amounts; effective December 2, 2025)
- CMS, 2026 Medicare Parts A & B Premiums and Deductibles fact sheet (the $202.90 standard Part B premium and $283 deductible for 2026)
- SSA, Form SSA-44, Medicare Income-Related Monthly Adjustment Amount, Life-Changing Event (the appeal to use more recent income)
- SSA, Request to lower an Income-Related Monthly Adjustment Amount (IRMAA) (the official life-changing-event process)