MAGI Calculator

What Is Modified Adjusted Gross Income (MAGI)?

Modified Adjusted Gross Income is your adjusted gross income (AGI) with a specific list of deductions and exclusions added back in. AGI is the number on Form 1040, line 11: total income minus above-the-line adjustments. MAGI takes that figure and restores certain items the tax law tells you to ignore for a particular benefit.

MAGI matters because it gates eligibility. The IRS and the Social Security Administration use it to decide whether you can contribute to a Roth IRA, deduct a traditional IRA contribution, claim an ACA premium tax credit, owe a Medicare IRMAA surcharge, or pay the net investment income tax. If your income sits anywhere near a threshold, the MAGI number, not your raw AGI, is the one that counts.

For a filer with no exclusions, MAGI often equals AGI. The two only diverge when you have add-backs such as the student loan interest deduction or a foreign earned income exclusion.

Why MAGI Is Calculated Differently for Each Benefit

Here is the part most calculators miss: there is no single MAGI. Each section of the tax code defines its own add-backs, so the MAGI used to test a Roth IRA contribution is not the same number used for IRMAA or the ACA premium tax credit. Apply one generic figure across the board and you get the wrong answer for most people.

The calculator above uses the purpose selector to switch which fields appear and which formula runs, so you never add back an item that does not belong in your number.

2026 MAGI Thresholds You Need to Know

The thresholds that matter most for 2026:

The NIIT thresholds are fixed by statute and never adjust for inflation. Medicare IRMAA brackets do shift each year, and they use a two-year lookback: your 2026 Part B and Part D premiums are set from the MAGI on your 2024 tax return. That timing gap is why a one-time income event, like a Roth conversion or a large capital gain, can push up your Medicare premiums two years later.

How to Calculate Your MAGI Step by Step

Start with AGI on Form 1040, line 11. Then figure out which add-backs apply to the benefit you care about, since that list changes by purpose. Tax-exempt interest is on line 2a, the student loan interest and IRA deductions are on Schedule 1, foreign income exclusions come from Form 2555, savings bond interest from Form 8815, and adoption benefits from Form 8839.

Add the applicable items to AGI to get your MAGI, then compare it against the relevant threshold above. If you are near a Roth or IRA limit, the Traditional IRA Deduction Calculator works out the exact deductible amount, and the Roth IRA Conversion Tax Calculator shows what a conversion would cost. If investment income is your concern, the Capital Gains Tax Calculator and the Tax Bracket Calculator fill in the rest of the picture.