What income counts for IRMAA, and does Social Security count?
IRMAA uses your adjusted gross income plus tax-exempt interest. That includes the taxable part of Social Security, but not the tax-free part.
The definition
For IRMAA, Social Security uses your modified adjusted gross income, or MAGI: the adjusted gross income on line 11 of Form 1040 plus tax-exempt interest from line 2a. Medicare generally uses the return from two years earlier.
What is in it
- Wages and self-employment income
- Pensions and annuities (the taxable part)
- Traditional IRA and 401(k) withdrawals
- Interest, dividends and capital gains
- Roth conversions (the taxable amount)
- The taxable part of Social Security
- Tax-exempt interest, such as municipal bond interest
What is not in it
- The tax-free part of Social Security
- Qualified Roth IRA withdrawals
- Qualified charitable distributions from an IRA, because they are excluded from income
- Gifts and loan proceeds
Does Social Security count?
Only the taxable part. Up to 85% of your benefit can be taxable depending on your other income, and that taxable portion sits inside your adjusted gross income. The rest does not count for IRMAA. You can estimate the split with the Social Security taxable benefits calculator.
IRMAA and ACA subsidies count income differently
| Type of income | Medicare IRMAA | ACA subsidy |
|---|---|---|
| Taxable Social Security | Counts | Counts |
| Tax-free Social Security | Does not count | Counts |
| Tax-exempt interest | Counts | Counts |
| Qualified Roth withdrawals | Do not count | Do not count |
| Roth conversions | Count | Count |
Married couples
If you file jointly, your incomes are added together and compared with the joint lines, starting at $218,000 for 2026. The surcharge is charged for each person on Medicare, so a couple pays it twice.
Common questions
Do IRA withdrawals count toward IRMAA?
Yes. Taxable distributions from a traditional IRA or 401(k) are part of adjusted gross income.
Do qualified charitable distributions raise my IRMAA income?
No. A qualified charitable distribution from an IRA is excluded from your income, so it does not raise adjusted gross income.
Why would income count for ACA subsidies but not for IRMAA?
The two programs define income differently. Marketplace subsidies add tax-free Social Security back in, while IRMAA does not.
Keep reading
Sources: SSA POMS HI 01101.010: Modified Adjusted Gross Income; HealthCare.gov: what counts as income; CMS: 2026 Part B premiums and IRMAA