MAGI (Modified Adjusted Gross Income)
Definition current for the 2026 plan year · Last reviewed July 2026
In one sentence: The income number that determines your ACA subsidy: AGI plus tax-exempt interest, non-taxed Social Security, and excluded foreign income.
MAGI is the number the entire subsidy system runs on — not your salary, not your take-home pay. For marketplace purposes it's your adjusted gross income (line 11 of Form 1040) plus tax-exempt municipal bond interest, the non-taxed portion of Social Security benefits, and excluded foreign earned income.
Why it matters so much in 2026: subsidy eligibility ends abruptly at 400% of the federal poverty level ($62,600 for a single person), and MAGI is what's measured against that line. Because MAGI comes after above-the-line deductions, you can lower it without earning less: pre-tax 401(k) and traditional IRA contributions, HSA contributions, and (for the self-employed) SEP-IRA contributions and the health-premium deduction all reduce MAGI dollar-for-dollar. Roth conversions and realized capital gains push it up — sometimes over the cliff in exactly the wrong year.
MAGI counts for your whole tax household — spouse and dependents who must file — even if only one person needs coverage. See the cliff guide for the planning playbook, or check your own number in the FPL calculator.