MAGI Calculator (Modified Adjusted Gross Income)

MAGI is AGI with specific add-backs. The IRS uses MAGI to determine eligibility for tax benefits that have income phase-outs. Different tax provisions use slightly different MAGI definitions, but the core idea is the same: take AGI, then add back certain items the IRS does not want you to “deduct your way into eligibility” with.

Standard MAGI for most provisions:

MAGI = AGI + Foreign Earned Income Exclusion + Foreign Housing Exclusion + Student Loan Interest Deduction + Tuition and Fees Deduction + Excluded Adoption Benefits + Savings Bond Interest Excluded + Income from Domestic Production

For Roth IRA contributions specifically, MAGI also adds back: traditional IRA contributions deducted, and a few other minor items.

The major MAGI thresholds (2024 figures, single filer unless noted):

Roth IRA contribution limits:

• Full contribution: MAGI under $146,000
• Phase-out: $146,000 to $161,000
• Zero contribution allowed: MAGI over $161,000
• Married filing jointly: phase-out $230,000 to $240,000

Traditional IRA deductibility (if covered by workplace retirement plan):

• Single full deduction: MAGI under $77,000
• Phase-out: $77,000 to $87,000
• Married filing jointly: $123,000 to $143,000

ACA premium tax credit (subsidies):

• Available up to 400% of federal poverty level
• Single 2024: roughly $58,320 MAGI cap (varies by state)
• Family of 4: roughly $120,000

Net Investment Income Tax (NIIT):

• Triggers at MAGI over $200,000 single, $250,000 married filing jointly
• 3.8% additional tax on the lesser of net investment income or MAGI excess over threshold

American Opportunity Tax Credit (education):

• Phase-out: $80,000 to $90,000 single, $160,000 to $180,000 MFJ

Lifetime Learning Credit:

• Same phase-outs as American Opportunity Credit

Why MAGI is calculated different ways for different programs. Each provision was written separately, and Congress did not standardize the add-backs. The student loan interest deduction adds back the deduction you took (so you can not deduct your way into eligibility). The Roth IRA MAGI adds back traditional IRA deductions for a similar reason. ACA MAGI is broader, including tax-exempt interest and Social Security benefits not in AGI.

Worked example.

• AGI from Form 1040: $145,000
• Foreign earned income exclusion claimed: $10,000
• Student loan interest deduction taken: $2,500

MAGI for Roth IRA = 145,000 + 10,000 + 2,500 = $157,500

A single filer with $157,500 MAGI is in the Roth IRA phase-out (between $146K and $161K). Allowable contribution: Reduction = (157,500 - 146,000) / 15,000 × $7,000 = 7,000 × 0.767 = $5,367 reduction Allowed Roth contribution = 7,000 - 5,367 = $1,633

The “backdoor Roth” strategy bypasses this entirely by funding a non-deductible traditional IRA and immediately converting to Roth.

Why MAGI is the moving target in tax planning.

• A $3,000 raise in mid-year that pushes MAGI from $159,000 to $162,000 can eliminate $7,000 of Roth contribution capacity — the marginal tax cost can exceed the raise itself.
• Charitable giving, HSA contributions, and 401(k) deferrals all reduce AGI and therefore MAGI. Aggressive 401(k) deferrals can preserve Roth eligibility.
• Capital losses harvested at year-end reduce AGI and MAGI. Useful when you are near a phase-out boundary.

Common confusion: MAGI vs Taxable Income. Taxable income = AGI - standard or itemized deduction - QBI deduction. MAGI is upstream of all that — it is closer to gross income, with a few specific add-backs.