Short answer
IRMAA (Income-Related Monthly Adjustment Amount) is an extra amount added to Medicare Part B and Part D premiums when your modified adjusted gross income is above set thresholds. For 2026, it generally applies when 2024 income was above $109,000 for single filers or $218,000 for married couples filing jointly.
Which year's income is used?
Social Security generally uses your tax return from two years earlier. 2026 premiums are based on 2024 modified adjusted gross income (MAGI): adjusted gross income plus tax-exempt interest.
Because of this lookback, a large Roth conversion, home sale, or capital gain in one year can affect Medicare premiums two years later.
What are the 2026 Part B and Part D IRMAA amounts?
The standard 2026 Part B premium is $202.90 per month. Amounts below are total monthly Part B premiums and the Part D surcharge added to your plan premium.
| Single filer MAGI | Joint filer MAGI | Part B monthly premium | Part D monthly surcharge |
|---|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 | $0.00 |
| $109,001 – $137,000 | $218,001 – $274,000 | $284.10 | $14.50 |
| $137,001 – $171,000 | $274,001 – $342,000 | $405.80 | $37.50 |
| $171,001 – $205,000 | $342,001 – $410,000 | $527.50 | $60.40 |
| $205,001 – $499,999 | $410,001 – $749,999 | $649.20 | $83.30 |
| $500,000 or more | $750,000 or more | $689.90 | $91.00 |
Married filing separately uses different brackets. Figures are from CMS's 2026 announcement; confirm current amounts at Medicare.gov or SSA.gov.
Can I ask Social Security to reduce IRMAA after retirement?
Yes, in some cases. If your income dropped because of a life-changing event — such as work stoppage or reduction, marriage, divorce, death of a spouse, or loss of pension income — you can ask Social Security to use a more recent year by filing Form SSA-44 with supporting documents.
Do IRMAA rules differ in Arizona?
No. IRMAA is a federal rule and is the same in every state. What can differ locally is the mix of Medicare Advantage and Part D plan options available in Maricopa County.
Sources
This page is informational only and is not individual tax, legal or investment advice. Rules and figures can change; confirm with the cited sources or a qualified tax professional.