Modified Adjusted Gross Income (MAGI)
Also called: MAGI, modified AGI
MAGI is AGI with certain deductions added back, and it's the income test for a long list of benefits — Roth IRA eligibility, the net investment income tax, health insurance subsidies, education credits. Its irritating feature is that the exact definition differs by provision, so the MAGI for a Roth contribution is not the MAGI for a premium credit. Always check which version a rule uses before assuming you qualify.