Modified adjusted gross income starts from adjusted gross income (AGI) on Form 1040 and adjusts it for a specific tax benefit. There is no single MAGI: the IRS lists different add-backs for Roth IRA contributions, traditional IRA deductions, the premium tax credit, education credits, the net investment income tax and others. For most people the adjustments are small or zero, so MAGI often equals AGI, but the correct version must be used for each test.
Formula
For Roth IRA contribution limits, the IRS defines it as:
MAGI = AGI + add-backs − Roth conversion income − rollovers to a Roth IRA
- AGI: adjusted gross income from Form 1040.
- Add-backs: the IRA deduction, student loan interest deduction, excludable savings bond interest, excluded employer-provided adoption benefits, the foreign earned income and housing exclusion, and the foreign housing deduction.
- Roth conversion income: income from converting a non-Roth IRA to a Roth IRA.
- Rollovers to a Roth IRA: taxable rollovers from a qualified retirement plan to a Roth IRA.
The traditional IRA deduction uses the same add-backs without the subtractions. The premium tax credit instead adds tax-exempt interest, nontaxable Social Security benefits and excluded foreign earned income.
Example
A single filer has a 2026 AGI of $175,000, which includes $25,000 from converting a traditional IRA to a Roth IRA. They also deducted $2,500 of student loan interest.
- MAGI = $175,000 − $25,000 + $2,500 = $152,500
The IRS 2026 Roth IRA phase-out range for single filers is $153,000 to $168,000, so this filer is below the range and can make a full Roth IRA contribution. The Roth IRA calculator applies the phase-out, and the Roth IRA income limits 2026 guide covers every filing status.
Common mistakes
- Using AGI or gross pay where a MAGI threshold applies.
- Using the Roth IRA definition for a different benefit, such as the premium tax credit.
- Forgetting income that can rise unexpectedly, such as a required minimum distribution, which is included in AGI.