What Adjusted Gross Income Means in Plain English
Adjusted gross income — AGI — is your gross income after a specific set of deductions, and before you take the standard or itemized deduction. It’s the intermediate number on your tax return: not your total earnings, not your taxable income, but the in-between step that determines what you’re eligible for.
Think of it as a filtered income number. You start with everything you earned, subtract certain qualifying deductions (the “adjustments”), and end up with AGI. That number then serves two purposes: it’s the base for calculating your taxable income (by subtracting your standard or itemized deduction), and it’s a gatekeeper for dozens of tax benefits and phase-outs.
AGI lives on line 11 of your Form 1040.
How Adjusted Gross Income Works
To calculate AGI, start with your total gross income and subtract “above-the-line” deductions — adjustments you can take regardless of whether you itemize:
- Traditional IRA contributions: Up to $7,000 ($8,000 if 50+) in 2024
- Student loan interest: Up to $2,500
- Half of self-employment tax: Self-employed individuals pay both halves of FICA — half is deductible here
- Self-employed health insurance premiums: 100% of premiums paid
- HSA contributions: Up to $4,150 individual / $8,300 family in 2024
- Alimony paid (for divorces finalized before 2019)
- Educator expenses: Up to $300
Why Adjusted Gross Income Matters to You
AGI is the number that determines whether you qualify for some of the most valuable tax breaks available:
Roth IRA eligibility: For single filers in 2024, the Roth IRA contribution limit begins phasing out at $146,000 MAGI and disappears entirely at $161,000. (MAGI is modified AGI — for most people, it’s the same as AGI.) If your AGI exceeds the limit, you can’t contribute directly to a Roth IRA.
Student loan interest deduction: Phases out between $75,000 and $90,000 AGI for single filers. Above $90,000, you get no deduction.
Premium tax credit (ACA insurance): Subsidies for marketplace health insurance are based on AGI relative to the federal poverty level. Lower AGI means larger subsidies.
IRA deductibility: If you (or your spouse) have a workplace retirement plan, the deductibility of traditional IRA contributions phases out based on AGI.
Medical expense deduction: You can only deduct medical expenses exceeding 7.5% of AGI. Lower AGI means a lower threshold and more deductible medical expenses.
Quick Example
Riley earns $80,000 in wages and has the following above-the-line deductions:
- Traditional IRA contribution: $7,000
- Student loan interest: $2,000
AGI = $80,000 − $7,000 − $2,000 = $71,000
At $71,000 AGI, Riley is:
- Well under the Roth IRA income limit (full contribution allowed)
- Under the student loan interest phase-out threshold ($75,000) — full $2,500 deductible
- Eligible for larger ACA subsidies if needed
If Riley hadn’t made the IRA contribution, AGI would be $78,000 — still under most thresholds, but the $7,000 contribution saves approximately $1,540 in taxes (22% bracket) while also lowering AGI.
Common Misconceptions
- AGI is the same as taxable income. AGI is a step above taxable income. Taxable income = AGI minus the standard or itemized deduction. The standard deduction alone reduces AGI by $14,600 for single filers.
- Above-the-line deductions require itemizing. These deductions are available to everyone — whether you take the standard deduction or itemize. That’s what “above the line” means: they reduce your income before you hit the standard-vs-itemized decision.
- If my income is over $146,000, I can’t access Roth IRA benefits at all. You can still do a “backdoor Roth IRA” — a two-step strategy involving a non-deductible traditional IRA contribution and a subsequent conversion to Roth. It’s a workaround that remains legal and widely used.