Form 1040 Line 11 Explained: Adjusted Gross Income (AGI)
How AGI Is Calculated
The math is straightforward: AGI equals total income on line 9 minus the above-the-line adjustments on line 10. Those adjustments —. Retirement contributions, the deductible half of self-employment tax, HSA deductions, student loan interest, and others carried from Schedule 1 —. Reduce gross income before the standard deduction or itemized deductions are even considered. The result is a single figure that the IRS and state tax authorities use as the baseline for dozens of downstream calculations.
Why AGI Controls So Much of the Return
AGI determines whether a taxpayer qualifies for credits such as the Child Tax Credit, the Earned Income Tax Credit, education credits, and the premium tax credit for health insurance. It also triggers phaseouts on itemized deductions, IRA contribution deductibility, and Roth IRA eligibility. For high-income filers, AGI is the starting point for the 3.8% net investment income tax and the 0.9% additional Medicare tax. In short, two taxpayers with identical gross incomes can face very different tax outcomes depending on where AGI lands after line 10 adjustments.
AGI and New York City Taxpayers
For Reed Corporation clients —. Business owners, models and creators, athletes, expats, and high-net-worth individuals — AGI planning is often the single most consequential conversation of the year. New York State uses federal AGI as the starting point for its own income tax calculation, which means a higher federal AGI flows directly into higher state and city tax. Managing retirement contributions, timing capital gains, and structuring entity income to improve AGI can produce meaningful savings across all three tax jurisdictions.
AGI vs. Modified Adjusted Gross Income (MAGI)
Several IRS provisions reference modified adjusted gross income rather than AGI. MAGI typically starts with AGI and adds back certain items —. Such as tax-exempt interest, excluded foreign earned income, or student loan interest —. Depending on the specific provision. Understanding the difference matters because a taxpayer who qualifies for a credit based on AGI may not qualify based on MAGI, or vice versa. The Reed Corporation reviews both figures when advising clients on contribution limits, credit eligibility, and phaseout thresholds.
Key Takeaway: AGI on line 11 is the single most referenced number in the tax code. If a taxpayer understands AGI, they understand one of the most powerful concepts in tax planning —. And the foundation for every deduction and phaseout that follows.
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Sources & References
Frequently Asked Questions
What is adjusted gross income on Form 1040?
Adjusted gross income, or AGI, is your total income minus a specific set of adjustments, and it lands on line 11 of Form 1040. You start with gross income, which is wages, business income, interest, dividends, capital gains, retirement distributions, and the rest, then subtract above-the-line adjustments such as deductible self-employment tax, retirement contributions, HSA contributions, and student loan interest (IRS: definition of AGI). The result is your AGI. It matters because it is the control number for the rest of the return: many credits and deductions phase out based on AGI, not on your gross pay. AGI is also the figure the IRS uses to verify your identity when you e-file. From AGI you subtract either the standard deduction or your Schedule A itemized deductions to reach taxable income. If you want the related concept, see AGI vs. MAGI.
What line is AGI on the 1040?
On the current Form 1040, adjusted gross income is line 11. The form walks you there in two steps: total income is line 9, your adjustments to income from Schedule 1 land on line 10, and line 11 is line 9 minus line 10, which is your AGI. From there, line 12 is your deduction (standard or itemized), and the subtraction continues toward taxable income. The line number has moved over the years as the IRS redesigned the 1040, which is why older guides may point somewhere else, but for recent tax years AGI sits on line 11. If you are reconstructing the calculation, our guide to line 10 adjustments covers what gets subtracted to get from total income to AGI.
What line is MAGI on the 1040, and how is it different from AGI?
There is no MAGI line on Form 1040. Modified adjusted gross income is a calculation you build on top of AGI, not a number the form prints. You take your AGI from line 11 and add back certain items, and which items depends on the rule you are testing. For Roth IRA eligibility you add back things like the foreign earned income exclusion and student loan interest; for the premium tax credit the add-backs are different. That is the trap: MAGI is not one fixed number, it is AGI plus whatever a specific provision tells you to add back. Because most people have few or none of those add-backs, their MAGI often equals their AGI, which is why the two get confused. Our AGI vs. MAGI guide lists the common add-backs by provision so you can compute the right MAGI for the credit or limit you care about.
How do I find my AGI from last year’s return?
Your prior-year AGI is on line 11 of last year’s Form 1040, the same line as the current year. You will need it most often to verify your identity when you e-file, because the IRS uses prior-year AGI as a signature check. If you do not have the paper or PDF copy, you can pull a free tax return transcript or wage and income transcript from your IRS Online Account (IRS: Get Transcript), and the AGI is listed there. If you filed late or amended, use the AGI from the originally filed return for e-file verification unless the IRS instructs otherwise. Keeping a copy of each year’s return is the simplest fix, since AGI is the one number you reach for every filing season.
Why does AGI matter so much for credits and deductions?
AGI is the gatekeeper for a large share of the tax code. Eligibility for credits like the child tax credit, education credits, and the premium tax credit phases out as AGI rises. Deduction thresholds key off it too: medical expenses on Schedule A only count above 7.5% of AGI, and several other limits move with it. Because so much keys off this one line, lowering AGI is where a lot of real tax planning happens, through retirement contributions, HSA contributions, and other above-the-line adjustments that reduce AGI directly rather than as itemized deductions. Two taxpayers with the same gross pay can owe very different tax depending on what they did to their AGI. That is why a CPA looks at AGI first: it determines which credits survive, which deductions are usable, and how much room is left before the next phase-out. New York City taxpayers should note the city piggybacks on these federal figures, so AGI planning ripples into state and city tax as well.