Gross income is every dollar you earned during the year from all sources. Adjusted gross income, or AGI, is that same total after you subtract a specific set of deductions the tax code allows before any other calculation happens. Understanding adjusted gross income vs. gross income matters because AGI, not gross income, is the figure the IRS uses to decide your tax bracket, your eligibility for most credits and deductions, and even what you pay for Medicare.
What Gross Income Includes
Federal law defines gross income as all income from whatever source, unless a specific statute excludes it.1Office of the Law Revision Counsel. 26 USC 61 – Gross Income Defined If money reached you and no exclusion applies, it belongs in gross income. The usual components are:
- Wages, salaries, tips, and bonuses from a W-2
- Interest, dividends, and capital gains from investments
- Net earnings from self-employment or a business you own
- Rental income after allowable expenses
- Taxable portions of pension, annuity, and IRA distributions
- Gambling winnings, unemployment compensation, pre-2019 alimony received, and certain Social Security benefits
You add all of it together before any deductions. The total appears near the top of Form 1040 and is the starting point for everything that follows.
What Makes AGI Different
AGI equals gross income minus a specific list of deductions reported on Schedule 1 of Form 1040. These are called “above-the-line” deductions because they sit above the line on the return where AGI is calculated. You claim them regardless of whether you later take the standard deduction or itemize. That is the structural difference between the two numbers: gross income is a sum, and AGI is that sum minus the Schedule 1 adjustments.
For the 2026 tax year, the adjustments that most often shrink gross income into AGI include the following.
Traditional IRA Contributions
Contributions to a Traditional IRA are deductible up to $7,500 for 2026, or $8,600 if you are 50 or older.2Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500 If you or your spouse are covered by a workplace retirement plan, the deduction may be reduced or eliminated depending on your income.3Internal Revenue Service. IRA Deduction Limits If neither of you has a workplace plan, the full deduction is available regardless of income.
Health Savings Account Contributions
If you are enrolled in a high-deductible health plan, HSA contributions reduce AGI. The 2026 limits are $4,400 for self-only coverage and $8,750 for family coverage, with an additional $1,000 allowed at age 55 or older.4Internal Revenue Service. Revenue Procedure 2025-19 Employer contributions count toward these limits and still reduce AGI.
Self-Employment Tax
If you work for yourself, you can deduct the employer-equivalent half of your self-employment tax when calculating AGI.5Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes) This lowers your income tax but does not reduce the self-employment tax itself. Self-employed people can also deduct their own health insurance premiums above the line.
Student Loan Interest
You can deduct up to $2,500 in interest paid on qualified student loans.6Internal Revenue Service. Topic No. 456, Student Loan Interest Deduction The deduction phases out as income rises and disappears entirely once it crosses the annual threshold for your filing status. You do not need to itemize to claim it.
Educator Expenses
K-12 teachers, counselors, principals, and aides who work at least 900 hours during a school year can deduct up to $300 in unreimbursed classroom expenses.7Internal Revenue Service. Topic No. 458, Educator Expense Deduction Two eligible educators filing jointly can claim up to $600 combined.
Alimony Paid Under Pre-2019 Agreements
Alimony paid under a divorce or separation agreement finalized before 2019 is still deductible above the line. Agreements executed on or after January 1, 2019, do not qualify, and the recipient does not include those payments in income.8Internal Revenue Service. Topic No. 452, Alimony and Separate Maintenance A pre-2019 agreement modified after 2018 loses the deduction if the modification adopts the new rules.
Military Moving Expenses
Active-duty members of the Armed Forces can deduct unreimbursed moving expenses tied to a permanent change of station.9Internal Revenue Service. Topic No. 455, Moving Expenses for Members of the Armed Forces and the Intelligence Community Qualifying costs include transporting household goods, storage, and travel to the new home. Civilians lost this deduction after 2017.
Smaller above-the-line items round out Schedule 1: jury duty pay you had to turn over to your employer, and penalties charged for early withdrawal of savings.
Why AGI Matters More Than Gross Income
AGI is not just an intermediate figure. It is the number the IRS uses to decide whether you qualify for many of the tax code’s most valuable benefits. A $5,000 reduction in AGI does more than save tax on that $5,000; it can also open doors to credits and deductions that would otherwise be out of reach.
Medical Expense Deductions
If you itemize, you can only deduct medical expenses that exceed 7.5% of your AGI.10Internal Revenue Service. Topic No. 502, Medical and Dental Expenses A taxpayer with an AGI of $80,000 needs more than $6,000 in unreimbursed medical costs before anything is deductible. Lower the AGI to $60,000 through above-the-line deductions and the threshold drops to $4,500.
Child Tax Credit and Earned Income Credit
The Child Tax Credit begins to phase out once AGI exceeds $200,000, or $400,000 for married couples filing jointly.11Internal Revenue Service. About the Child Tax Credit The Earned Income Tax Credit, worth up to $8,231 for 2026 with three or more qualifying children, has lower AGI ceilings and phases out quickly.12Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 A few thousand dollars of extra income can wipe the EITC out entirely.
Roth IRA Eligibility
Direct Roth IRA contributions depend on your modified AGI. For 2026, single filers can make a full contribution if MAGI is below $153,000, phasing to zero between $153,000 and $168,000. Married couples filing jointly phase out between $242,000 and $252,000.2Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500 If your income is near these boundaries, above-the-line deductions can preserve eligibility.
Medicare Premium Surcharges
Medicare Part B premiums increase through income-related monthly adjustment amounts, or IRMAA, when modified AGI is too high. For 2026, single filers pay no surcharge at or below $109,000, or $218,000 for joint filers. Above those lines, monthly surcharges start at $81.20 and rise in tiers to $487.00 at the top.13Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles IRMAA uses your tax return from two years prior, so a one-time income spike from selling a home or taking a large distribution can trigger surcharges you did not expect.
Net Investment Income Tax
A 3.8% surtax applies to the lesser of your net investment income or the amount by which your MAGI exceeds $200,000 for single filers, or $250,000 for joint filers.14Internal Revenue Service. Net Investment Income Tax Net investment income includes capital gains, dividends, interest, rental income, and royalties. These thresholds are not indexed to inflation.
Affordable Care Act Premium Subsidies
Marketplace premium tax credits are calculated from household MAGI.15Internal Revenue Service. Questions and Answers on the Premium Tax Credit Higher MAGI means smaller subsidies. For self-employed workers and early retirees not yet on Medicare, HSA and Traditional IRA contributions directly lower the premium.
A Quick Note on Modified AGI
Several of the rules above refer to modified adjusted gross income rather than plain AGI. MAGI starts with AGI and adds back certain items depending on which benefit is being calculated, and there is no single formula.16Internal Revenue Service. Modified Adjusted Gross Income For most people without foreign earned income or tax-exempt interest, MAGI and AGI are the same number. The common add-backs are foreign earned income excluded from the return, tax-exempt bond interest, and certain education-related deductions. When a form asks for MAGI, its instructions list the specific items to add back.
Where AGI Sits in the Full Calculation
After AGI, one more step produces taxable income: you subtract either the standard deduction or your itemized deductions, whichever is larger. For 2026, the standard deduction is $16,100 for single filers, $32,200 for married filing jointly, and $24,150 for head of household, with an extra $2,050 (single) or $1,650 per qualifying spouse (joint) at age 65 and over.12Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 The tax rate tables apply to taxable income, not to AGI and not to gross income.
The sequence is worth keeping straight: gross income is the top-line sum, AGI is that sum minus Schedule 1 adjustments, and taxable income is AGI minus the standard or itemized deduction. Gross income determines whether you have to file. AGI determines what you qualify for. Taxable income determines what you owe.