MAGI Calculator: Modified Adjusted Gross Income

MAGI Calculator

Enter your AGI and the items each program adds back to see four MAGI figures — Roth IRA, traditional IRA deduction, ACA premium tax credit, and Medicare IRMAA — and where each one lands against its 2026 limit. The calculator is for informational purposes only; its results are estimates.

Your MAGI also decides how much you can put into a Roth IRA: the Roth IRA calculator applies the 2026 phase-out ranges.

What Is MAGI and Why Does It Matter?

Your Modified Adjusted Gross Income (MAGI) is your Adjusted Gross Income (AGI) with certain deductions added back. It sounds simple, but it's one of the most consequential numbers on your tax return — it determines whether you can contribute to a Roth IRA, how large your ACA premium subsidy is, and whether you'll pay Medicare IRMAA surcharges.

For a complete explanation of MAGI and strategies to reduce it, see: What Is MAGI and Why It Matters for Your Taxes.

AGI vs. MAGI: The Key Difference

AGI (Adjusted Gross Income) is your total gross income minus specific "above-the-line" deductions: 401(k) contributions, HSA contributions, student loan interest, alimony (pre-2019), half of self-employment tax, and others.

MAGI starts with your AGI and adds back certain deductions that Congress decided shouldn't reduce your income for specific purposes. The add-backs vary depending on which benefit you're calculating MAGI for.

Which add-backs does each program use?

There is no single MAGI. Each program starts from AGI (Form 1040 line 11) and adds back its own list. These are the four the calculator computes:

Sources: Pub. 590-A Worksheets 1-1 and 2-1 for the IRA columns, the Form 8962 instructions for the ACA column, and the Social Security Administration's IRMAA rules (AGI plus tax-exempt interest) for Medicare. The old tuition-and-fees deduction expired after 2020, and passive losses are not a Roth or ACA add-back, so the calculator doesn't ask for them.

Roth IRA Eligibility by MAGI

Your ability to contribute directly to a Roth IRA phases out based on Roth MAGI. For 2026 (IRS Notice 2025-67) the contribution limit is $7,500, or $8,600 with the $1,100 catch-up at 50 or older.

Inside the range the calculator reduces the $7,500 limit proportionally, rounds up to the next $10, and uses $200 if the result is between $0 and $200 — the Pub. 590-A method. At $160,500 of Roth MAGI, a single filer is halfway through the range: $7,500 × $7,500 ÷ $15,000 = $3,750. Above the upper limit you can't contribute directly, but you can use the backdoor Roth (contribute to a traditional IRA, then convert). See the backdoor Roth calculator. If a direct contribution already went in above the limit, estimate the fix with the excess Roth IRA contribution calculator.

Roth conversion income is removed for this test, so converting doesn't cost you this year's Roth contribution — but the conversion does count for the ACA and IRMAA tests.

ACA Premium Tax Credit and MAGI

The premium tax credit depends on household MAGI as a percentage of the federal poverty line. For 2026 coverage the HealthCare.gov tables use the 2025 HHS guidelines — $15,650 for one person plus $5,500 per extra person in the 48 contiguous states and DC — and, under current law for 2026, there is no credit above 400% (Pub. 505).

Alaska and Hawaii use higher guidelines. Below 100% you are usually in Medicaid territory (or get no credit in states that didn't expand Medicaid). Married couples generally must file jointly to claim the credit. The calculator shows your ACA MAGI as a percentage of the poverty line for the household size you enter. To turn it into a dollar credit for 2026 or 2027 coverage, enter your ACA MAGI as household income in the ACA premium tax credit calculator.

Medicare IRMAA Surcharges

If your MAGI from two years earlier exceeds certain thresholds, you pay more for Medicare Part B and Part D. Your 2026 premiums use your 2024 tax return. The 2026 tiers, from the CMS 2026 premium fact sheet:

Married couples who file separately and lived together at any point in the year jump straight to $649.20 above $109,000, and $689.90 at $391,000 or more. IRMAA MAGI is AGI plus tax-exempt interest — municipal bond interest counts, Roth conversions count, and one large year can raise premiums two years later.

Worked examples

Example 1: one person, four different MAGIs. A single filer has $158,000 of AGI, which includes a $10,000 Roth conversion. She deducted $2,500 of student loan interest and received $4,000 of municipal bond interest.

• Roth MAGI: $158,000 − $10,000 + $2,500 = $150,500 → under $153,000, so she can contribute the full $7,500
• IRA-deduction MAGI: $158,000 + $2,500 = $160,500 → above $91,000, so a traditional IRA contribution isn't deductible if she's covered by a workplace plan
• ACA MAGI: $158,000 + $4,000 = $162,000 → far above $62,600 for a household of one, so no premium tax credit
• IRMAA MAGI: $158,000 + $4,000 = $162,000 → the $137,001–$171,000 tier: $405.80 a month for Part B plus $37.50 for Part D, two years later

Example 2: the ACA cliff. A married couple (household of two) retires early with $80,000 of AGI, $3,000 of tax-exempt interest, and $6,000 of Social Security benefits that weren't taxable.

• ACA MAGI: $80,000 + $3,000 + $6,000 = $89,000
• 400% for two people: $84,600, so they're about 421% of the poverty line and get no credit for 2026 coverage
• Cutting MAGI by $4,401 — for example by skipping a planned Roth conversion or contributing to a deductible IRA or HSA — would bring them back under the line

These are the figures the calculator shows for the same inputs.

Traditional IRA Deductibility

If you're covered by a workplace retirement plan (like a 401k), your ability to deduct traditional IRA contributions phases out based on MAGI. If you're not covered by a workplace plan, you can deduct IRA contributions at any income level.

Pick your situation in the Workplace Retirement Plan Coverage field and the calculator uses the matching row, or skips the phase-out entirely if neither spouse is covered. Inside a range, the deductible amount shrinks in proportion to how far your MAGI is through it, rounded up to the next $10, with a $200 minimum (Pub. 590-A Worksheet 1-2). Example: a single filer covered at work with IRA-deduction MAGI of $86,000 is halfway through the $81,000–$91,000 range, so $7,500 × ($91,000 − $86,000) ÷ $10,000 = $3,750 of a $7,500 contribution is deductible. A joint filer whose spouse is covered (but who is not) gets the same 50% result at $247,000.

Above the phase-out range, your IRA contribution is non-deductible — making a Roth IRA or backdoor Roth a better option.

Child Tax Credit Phase-Out

The Child Tax Credit ($2,200 per qualifying child in 2026) begins phasing out at:

• $200,000 MAGI for single filers
• $400,000 MAGI for married filing jointly

The credit is reduced by $50 for every $1,000 of MAGI above these thresholds.

Strategies to Lower Your MAGI

Reducing your MAGI can unlock Roth IRA eligibility, preserve ACA subsidies, and avoid IRMAA surcharges:

• Maximize pre-tax 401(k) contributions — every dollar contributed reduces your MAGI dollar-for-dollar
• Contribute to an HSA — health savings account contributions are above-the-line deductions that reduce MAGI
• Harvest investment losses — capital losses reduce your taxable income and AGI
• Time income and deductions — defer income to future years or accelerate deductions into the current year
• Use a Health FSA — employer-sponsored FSA contributions reduce your W-2 income

See Roth Conversion Calculator to model conversions that stay within your optimal MAGI range.

MAGI versus taxable income versus withholding

MAGI is not the number in the tax brackets. Brackets apply to taxable income after the standard deduction or itemized deductions. MAGI is a program eligibility figure.

A raise can:

• Push you up a federal tax bracket (ordinary tax).
• Push MAGI through a Roth or ACA cliff (lost contribution room or subsidy).
• Leave withholding unchanged until you file a new W-4 — see the tax withholding calculator.

Those three events are easy to mix up. Run the matching tool for the matching question.

Foreign earned income that you exclude on Form 2555 is often added back for MAGI even though it dropped regular taxable income. The FEIE calculator and the foreign earned income exclusion guide cover that trap.

Self-employed people reduce AGI with the employer-equivalent half of SE tax and retirement contributions, which can also lower MAGI. Wage employees get the 401(k) deferral off the W-2 instead. Use the 1099 tax calculator if you are mixing both.

Year-end checklist

• Confirm workplace deferrals will actually hit the W-2 before payroll’s last cycle.
• If you are near an IRMAA cliff, remember the two-year lag: this year’s MAGI can set premiums two years out.
• If you are near the ACA cliff, a small Roth conversion can be more expensive than the tax on the conversion.
• If you are near the Roth IRA cap, a backdoor Roth may still be available; it does not require MAGI under the direct-contribution ceiling, but a large traditional IRA balance creates a pro-rata problem. Model that on the backdoor Roth calculator.

Student-loan interest and traditional IRA deductions can lower AGI while some MAGI formulas add them back. That is not a bug. It is how Congress kept people from stacking every above-the-line write-off to stay under a phaseout. If one of the calculator’s MAGI figures is higher than the AGI on your draft 1040, look at the add-back table rather than assuming the tool double-counted wages.

The child tax credit phases out on MAGI ($200,000 single / $400,000 joint under current law in this library). That phaseout is slower than the ACA cliff but still real for high W-2 households with several children.

How to use this calculator

Enter the AGI from a draft 1040 (line 11), your household size, and only the add-back items you actually have. Read the Roth, IRA-deduction, ACA, and IRMAA outputs as four separate answers. Do not take the lowest MAGI and apply it to every program.

If you are within a few thousand dollars of a cliff, treat the output as a warning to talk to a professional, not as a green light to convert a large IRA or to decline workplace coverage. Cliffs are where simplified MAGI math hurts.

Informational use only

MAGI definitions differ by statute. This calculator is a simplified educational model. It does not complete Form 8606, an ACA application, or a Social Security IRMAA appeal. Confirm with current IRS publications, Healthcare.gov or your state exchange, Medicare, and a tax professional when a cliff is close.

Saver's Match MAGI under 26 U.S.C. §6433 is another formula: AGI without sections 911, 931, and 933, and without the exclusion or deduction for the qualified retirement contributions being matched. Roth MAGI from this tool is a starting point, not the number to paste into the Saver's Match calculator. See the Saver's Match guide.

Related: What is MAGI | Roth conversion calculator | backdoor Roth calculator | excess Roth IRA contribution calculator | child tax credit calculator | Saver's Match calculator | federal income tax hub