Glossary

MAGI (Modified Adjusted Gross Income)

The specific income figure used to determine eligibility for premium tax credits and Medicaid. It is your adjusted gross income (AGI) plus a few add-backs, most commonly non-taxable Social Security, tax-exempt interest, and excluded foreign income.

Last updated: May 18, 2026

MAGI is the specific income figure the Marketplace uses to decide whether you qualify for APTC, CSR, or Medicaid. It is not your gross paycheck and it is not your net take-home pay — it is your Adjusted Gross Income (AGI) plus a few add-backs.

How to find your MAGI

Start with the AGI line on your most recent federal tax return (Form 1040, line 11). Then add back, if applicable:

Non-taxable Social Security benefits
Tax-exempt interest (from municipal bonds, for example)
Foreign earned income that was excluded under IRS § 911

That sum is your MAGI for ACA purposes. For most households, AGI and MAGI are identical or very close: the add-backs typically affect retirees, expats, and households with significant tax-exempt investments.

Whose income counts

MAGI is household income, not individual income. The household includes:

You
Your spouse, if you file jointly
Anyone you claim as a tax dependent

If your 19-year-old earns $4,000 at a part-time job and you claim them as a dependent, their $4,000 counts toward household MAGI. If you do not claim them, it does not.

Why it matters

MAGI determines:

Whether you qualify for the premium tax credit (must be between 100% and 400% of FPL for 2026 coverage post-IRA expiration)
Whether you qualify for CSR (under 250% FPL)
Whether you qualify for Medicaid (rules vary by state and expansion status; generally up to 138% FPL in expansion states)
The exact amount of your APTC (sliding scale)

A $1,000 swing in MAGI can shift your subsidy by hundreds of dollars per year, or push you across the 400% FPL cliff. Get this number right.

Self-employed and 1099 income

If you are self-employed, your MAGI is based on your net business income (after deductible business expenses), not your gross revenue. Track this carefully; projecting MAGI is harder for 1099 workers because income varies month to month. Update the Marketplace if your projection shifts more than 10%.

What to do if your income changes

The APTC is calculated from your projected MAGI for the coverage year. If your income changes mid-year (you get a raise, lose a job, start freelancing, open a business), update the Marketplace within 30 days. This adjusts your monthly APTC and prevents large reconciliation surprises on Form 8962 at tax time.

MAGI vs taxable income

Gross income: total before any deductions
AGI: gross minus certain “above-the-line” deductions (HSA contributions, student loan interest, self-employed retirement contributions, half of self-employment tax)
MAGI: AGI + a few add-backs (above)
Taxable income: AGI minus standard or itemized deductions; used for your tax bracket, not for ACA subsidies

Use the calculator with your projected MAGI to see your estimated APTC.