Where Is MAGI on Form 1040? Add-Backs and How to Calculate It

Modified Adjusted Gross Income does not appear anywhere on Form 1040. There is no line labeled MAGI on the return, its schedules, or the worksheets you file with the IRS.¹ To find your MAGI, you start with the Adjusted Gross Income printed on Line 11 of Form 1040 and add back specific items depending on which tax benefit you are testing. There is no single MAGI formula, which is the part that trips people up.

Where AGI Sits on Form 1040

Your Adjusted Gross Income is on Line 11 of Form 1040.¹ That is the number the IRS actually prints, and it is the starting point for every MAGI calculation you will run.

AGI is your total income (wages, interest, dividends, business income, capital gains, and other sources) minus the “above-the-line” adjustments listed on Schedule 1. Those adjustments include the deductible portion of self-employment tax, Health Savings Account contributions, educator expenses, and student loan interest.² The total from Schedule 1, line 26 flows onto Form 1040, line 10, gets subtracted from total income, and lands as the AGI on line 11. From there, MAGI is a pencil-and-paper calculation you do yourself.

Why There Is No Single MAGI

MAGI takes your AGI and adds back income items or deductions that were excluded or subtracted along the way. Because it only adds things back, your MAGI is always equal to or higher than your AGI.¹ For a W-2 employee with no foreign income, no municipal bonds, and no unusual exclusions, MAGI and AGI are often the same number.

What throws people is that the IRS maintains different MAGI formulas for different provisions. Roth IRA contributions use one definition. The Premium Tax Credit uses another. Medicare surcharges, the Net Investment Income Tax, education credits, the Child Tax Credit, and the adoption credit each have their own.¹ Every formula starts at Line 11 AGI, but each adds back a different mix of items. Before calculating MAGI, identify which benefit you are checking, then pull the worksheet tied to that provision. For traditional and Roth IRAs, the worksheets are in IRS Publication 590-A.³ For the Premium Tax Credit, use Form 8962. For the Net Investment Income Tax, use Form 8960.

Common Add-Backs to AGI

The specific add-backs vary by provision, but a handful of items show up across most MAGI formulas:

Tax-exempt interest, reported on line 2a of Form 1040. Interest from municipal bonds escapes federal income tax but gets added back for Premium Tax Credit, Medicare, and Social Security calculations.⁴
Foreign earned income and housing exclusions claimed on Form 2555. Excluded foreign earnings get added back for nearly every MAGI test.¹
Non-taxable Social Security benefits. The portion of your Social Security not included in taxable income is added back for Premium Tax Credit purposes.⁴
Student loan interest and traditional IRA deductions. Both are Schedule 1 adjustments that reduced your AGI, and both get added back for Roth IRA eligibility.¹
Savings bond interest excluded under Form 8815 for higher education expenses. Added back for both Roth IRA and education credit MAGI.¹

The gap between AGI and MAGI can be significant for someone with a large municipal bond portfolio or foreign earnings. For most other taxpayers, it is zero.

Calculating MAGI for Roth and Traditional IRAs

The Roth IRA MAGI formula begins with Line 11 AGI. From there, you add back the traditional IRA deduction, the student loan interest deduction, excluded savings bond interest, the employer-provided adoption benefit exclusion, and the foreign earned income and housing exclusions. You then subtract any income from converting a traditional IRA to a Roth or rolling a qualified plan into a Roth, so conversion income does not count against your ability to make new contributions.¹

For 2026, direct Roth contributions phase out between $153,000 and $168,000 for single filers and heads of household, and between $242,000 and $252,000 for married couples filing jointly.⁵ The 2026 contribution limit is $7,500.

The traditional IRA deduction uses a similar starting point but different thresholds when you or your spouse is covered by a workplace retirement plan. For 2026, the phase-out runs $81,000 to $91,000 for a single filer who is covered, $129,000 to $149,000 for a joint filer when the contributing spouse is covered, $242,000 to $252,000 for a joint filer when only the other spouse is covered, and $0 to $10,000 for married filing separately if covered by a plan.⁵ If neither spouse is covered by a workplace plan, no MAGI phase-out applies and the full deduction is available.

Calculating MAGI for the Premium Tax Credit

The Premium Tax Credit uses the broadest MAGI definition. Start with Line 11 AGI, then add excluded foreign income, non-taxable Social Security benefits (including tier 1 railroad retirement benefits), and tax-exempt interest.⁴ Household MAGI for PTC purposes also includes the MAGI of every family member required to file a return.

For 2026, the enhanced subsidies from the American Rescue Plan and Inflation Reduction Act have expired. Eligibility requires household income between 100% and 400% of the federal poverty line, and households above 400% no longer qualify for any subsidy.⁶

Calculating MAGI for Medicare IRMAA

Medicare uses the simplest MAGI definition of any provision. It is the AGI from Line 11 plus tax-exempt interest from line 2a of Form 1040. Nothing else is added back.⁷

The complication with IRMAA is timing, not arithmetic. Social Security sets your 2026 premiums using the tax return from two years earlier, which is your 2024 filing. If that return is unavailable, they fall back to 2023 data. A one-time income spike, such as selling a home or converting a large IRA, can trigger surcharges later, when your current income no longer reflects it. If a qualifying life-changing event like retirement, divorce, or the death of a spouse has reduced your income, you can ask for a reduction by filing Form SSA-44.⁷

Calculating MAGI for the Net Investment Income Tax

The 3.8% Net Investment Income Tax kicks in when MAGI exceeds $200,000 for single filers and heads of household, $250,000 for married joint filers, and $125,000 for married filing separately.⁸ The tax applies to the lesser of your net investment income or the amount your MAGI exceeds the threshold.

The NIIT MAGI is narrower than the PTC version. Start with AGI, then add back the foreign earned income exclusion and certain related deductions.⁸ These thresholds have not been adjusted for inflation since the tax took effect in 2013.

Calculating MAGI for the Rental Real Estate Loss Allowance

If you actively participate in managing a rental property, you can deduct up to $25,000 in rental losses against other income. That allowance phases out once MAGI exceeds $100,000 and disappears at $150,000. For married couples filing separately who lived apart all year, the allowance is $12,500 with a $50,000 phase-out start.⁹¹⁰

The passive loss MAGI formula starts with AGI but excludes taxable Social Security benefits, excludable savings bond interest, the IRA deduction, the student loan interest deduction, and any passive activity loss itself.⁹ The $100,000 and $150,000 figures are fixed by statute and have never been indexed for inflation.

What Happens If You Calculate MAGI Wrong

A miscalculated MAGI is not just a paper problem. If your MAGI turns out to be too high for a Roth contribution but you contributed anyway, the excess amount takes a 6% penalty tax for every year it stays in the account.¹¹ You can avoid the penalty by withdrawing the excess and any attributable earnings before your filing deadline, including extensions. The same 6% penalty applies to excess traditional IRA and HSA contributions.

For the Premium Tax Credit, the stakes climbed for tax years after 2025. If your actual MAGI exceeds what you estimated at Marketplace enrollment and advance payments were larger than your entitlement, you repay the full excess when you file. The repayment caps that previously limited how much lower-income households owed back no longer apply.¹²

The consistent rule is to identify which MAGI definition applies before you make a contribution, enroll in coverage, or claim a deduction. For Roth eligibility, work the Publication 590-A worksheet.³ For Marketplace estimates, use the Form 8962 instructions. Running the wrong formula against the right threshold produces the same result as running the wrong number: a bill you were not expecting.

1
Internal Revenue Service. Modified Adjusted Gross Income
2
Internal Revenue Service. 2025 Schedule 1 (Form 1040) – Additional Income and Adjustments to Income
3
Internal Revenue Service. Publication 590-A (2025)
4
Internal Revenue Service. Questions and Answers on the Premium Tax Credit
5
Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500
6
HealthCare.gov. Modified Adjusted Gross Income (MAGI) – Glossary
7
Social Security Administration. Medicare Income-Related Monthly Adjustment Amount – Life-Changing Event Form SSA-44
8
Internal Revenue Service. Questions and Answers on the Net Investment Income Tax
9
Office of the Law Revision Counsel. 26 U.S. Code 469 – Passive Activity Losses and Credits Limited
10
Internal Revenue Service. Instructions for Form 8582
11
Internal Revenue Service. Form 5329 – Additional Taxes on Qualified Plans (Including IRAs) and Other Tax-Favored Accounts
12
Internal Revenue Service. Updates to Questions and Answers About the Premium Tax Credit