How IRMAA works
IRMAA stands for income-related monthly adjustment amount. Most people pay the standard Part B premium of $202.90 a month in 2026. If your income is above the first bracket line, Social Security adds an amount to your Part B premium and a separate surcharge for Part D drug coverage. The Part D surcharge applies whether you have a stand-alone drug plan or a Medicare Advantage plan with drug coverage, and it is paid to Medicare, not to the plan.
Three things surprise people:
- It looks back two years. Your 2026 premium uses your 2024 tax return. A big income year in your last year of work can raise your premium in your first years of retirement.
- The brackets are cliffs. Going one dollar over a line raises the premium for the whole year. It is not a tax on the dollars above the line.
- It is recalculated every year. If your income falls, your premium falls too, two years later or sooner if you file Form SSA-44.
Income that moves Arizona retirees into a bracket
IRMAA uses federal modified adjusted gross income: the adjusted gross income on your federal Form 1040 plus tax-exempt interest. Arizona's state income tax doesn't enter into it, so a deduction or exemption on your Arizona return doesn't lower your IRMAA. These are the income sources that most often push retirees over a line:
- Pensions. The taxable part of a pension counts in full, whether it comes from the Arizona State Retirement System, a public safety or university plan, the military or a private employer. A couple with two public pensions can cross the joint line without much other income.
- Required minimum distributions. Withdrawals from traditional IRAs and 401(k)s are taxable income, and they grow as you age.
- Roth conversions. The converted amount counts in the year you convert. Spreading conversions over several years can keep you under a line.
- Selling a home or investments. Capital gains above the home-sale exclusion count, which matters for people who sell a house elsewhere when they move to Arizona, or sell a winter home when they stop spending winters here.
- Taxable Social Security. The taxable part of your benefit is included in adjusted gross income.
Tip: If you are 70½ or older and give to charity, a qualified charitable distribution sent straight from your IRA to the charity can count toward your required minimum distribution without being added to your adjusted gross income. The 2026 limit is $111,000 per person. Ask a tax professional whether it fits your situation.
2026 IRMAA brackets
Income is 2024 MAGI. The Part B amount is the full monthly premium; the Part D amount is added to whatever your drug plan charges.
| Single (and head of household) | Married filing jointly | Part B premium | Part D surcharge |
|---|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 | $0 |
| $109,001 to $137,000 | $218,001 to $274,000 | $284.10 | +$14.50 |
| $137,001 to $171,000 | $274,001 to $342,000 | $405.80 | +$37.50 |
| $171,001 to $205,000 | $342,001 to $410,000 | $527.50 | +$60.40 |
| $205,001 to $499,999 | $410,001 to $749,999 | $649.20 | +$83.30 |
| $500,000 or more | $750,000 or more | $689.90 | +$91.00 |
If you are married, lived with your spouse at any time in 2024 and filed separately, the brackets are different: $109,000 or less pays the standard premium, $109,001 to $390,999 pays $649.20 (Part D +$83.30), and $391,000 or more pays $689.90 (Part D +$91.00). The calculator handles this when you pick "Married filing separately".
Asking Social Security to use newer income
If your income has dropped because of a life-changing event, you can ask Social Security for a new decision with Form SSA-44. The events Social Security accepts are marriage, divorce or annulment, death of a spouse, work stoppage, work reduction, loss of income-producing property, loss of pension income, and an employer settlement payment. Retiring from a job in Phoenix, Tucson or anywhere else counts as a work stoppage, which is the most common reason Arizona retirees file.
- Fill out Form SSA-44 with the event, its date, and your estimated income for the year.
- Attach proof, such as a letter from your employer showing your last day of work, or a death certificate.
- Send it to Social Security or bring it to a local office. If Social Security agrees, it recalculates your premium from your newer income.
If you disagree with the income Social Security used, for example because the IRS data was wrong or you amended your return, you can also ask for a reconsideration. More on premiums and the rest of 2026's amounts is on Medicare costs in 2026 and Medicare Part B. If you're still working, see working past 65.
Sources
- CMS — 2026 Medicare Parts A & B premiums and deductibles (IRMAA tables)
- Social Security — Premiums: rules for higher-income beneficiaries
- Social Security — Form SSA-44, Medicare income-related monthly adjustment amount, life-changing event (PDF)
- IRS — Retirement plan and IRA required minimum distributions FAQs (qualified charitable distributions)
Frequently asked questions
Which year's income sets my 2026 IRMAA?
Social Security uses the modified adjusted gross income (MAGI) on your 2024 federal tax return, the most recent one the IRS gives it. MAGI is your adjusted gross income plus any tax-exempt interest. If the 2024 return isn't available, Social Security may use 2023 and update it later.
Does my Arizona pension count toward IRMAA?
Yes, the taxable part of a pension counts, whether it comes from the Arizona State Retirement System, another public plan, the military or a private employer. So do required minimum distributions, Roth conversions, capital gains and taxable Social Security. Arizona's own state tax rules don't change the calculation, because Social Security uses your federal return.
What if I just retired and my income dropped?
Retirement counts as a work stoppage, one of the life-changing events that let you ask Social Security to use a newer, lower income year. You file Form SSA-44 with proof of the event and an estimate of your current income.
Is IRMAA a sliding scale?
No. The brackets are cliffs: one dollar over a bracket line moves you to the next premium for the whole year. That is why the calculator shows how far over the line you are.
