Modified Adjusted Gross Income Calculator - MAGI

Modified adjusted gross income, or MAGI, is not a single line on Form 1040. It is AGI plus a list of add-backs that changes with the tax benefit you are testing. Premium tax credits, IRA contribution limits, Roth IRA eligibility, Medicare IRMAA, education credits, and net investment income tax each define MAGI a little differently. This calculator uses a transparent planning identity: MAGI = AGI + foreign earned income exclusion + tax-exempt interest + Social Security benefits + other add-backs you enter. That identity is intentionally simplified. For many IRA and ACA worksheets, tax-exempt interest is added and the foreign earned income exclusion is added back. Social Security is already partly or fully included in AGI once it is taxable; adding the full benefit on top of AGI can double-count for some MAGI definitions and under-count for others that start from a different base. The “other MAGI additions” field is where you place student-loan exclusions, housing exclusions, or program-specific items after you read the worksheet you actually need. The formula displayed by the calculator is MAGI = AGI + Σ additions. Total additions is the sum of the four optional fields. Empty fields count as zero. Negative values are rejected because this page models add-backs, not above-the-line deductions. If AGI is $75,000 and tax-exempt interest is $2,500, MAGI is $77,500 under this model. Use the result as a screening number before you open the official worksheet for Roth IRA phaseouts, marketplace subsidies, or Medicare brackets. Those programs use IRS thresholds that change with tax year and filing status. Because MAGI definitions diverge, two people with the same AGI can have different MAGIs for different benefits. Keep a copy of the worksheet title you are modeling so a later update uses the same add-back list. Confirm the current-year instructions, and do not file a return or an insurance application from this estimate alone.