What Is Adjusted Gross Income vs. Taxable Income?

Adjusted gross income and taxable income are two different numbers on the same return, and knowing which is which explains a lot of how your tax bill gets built. Adjusted gross income (AGI) is your gross income minus a specific set of “above-the-line” adjustments, and it appears on line 11 of Form 1040. Taxable income is AGI minus your standard or itemized deduction and certain other deductions, and it’s the number the tax brackets actually apply to. Gross income is everything you received; AGI narrows it; taxable income narrows it again.

The gap between those figures does real work. A single filer with $80,000 in gross income might land at an AGI of $73,000 after above-the-line deductions, then a taxable income of $56,900 after the 2026 standard deduction of $16,100. Every dollar of difference is a dollar the IRS doesn’t tax.

How AGI Is Calculated

Gross income under the tax code means income from whatever source unless a specific provision excludes it.1Office of the Law Revision Counsel. 26 USC 61 – Gross Income Defined Wages, tips, interest, dividends, rental income, business profits, and capital gains all count. Gifts, inheritances, most municipal bond interest, life insurance payouts, and qualified scholarships are excluded and never enter the calculation.2Office of the Law Revision Counsel. 26 US Code Part III – Items Specifically Excluded From Gross Income

From gross income, you subtract the adjustments listed in Section 62 to get AGI.3Office of the Law Revision Counsel. 26 USC 62 – Adjusted Gross Income Defined These adjustments are called “above the line” because they come off before you choose between the standard deduction and itemizing, and you can claim them either way. They live on Schedule 1.

The common ones:

  • Traditional IRA contributions, up to $7,500 for 2026 ($8,600 if you’re 50 or older). If you or your spouse is covered by a workplace plan, the deduction phases out between $81,000 and $91,000 of modified AGI for single filers and between $129,000 and $149,000 for joint filers.4Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500
  • Health Savings Account contributions, capped in 2026 at $4,400 for self-only coverage and $8,750 for family coverage, plus $1,000 more if you’re 55 or older.5Internal Revenue Service. Rev Proc 2025-19
  • Half of self-employment tax, deductible as the employer-equivalent portion of Social Security and Medicare.6Internal Revenue Service. Topic No 554, Self-Employment Tax
  • Self-employed health insurance premiums, when you aren’t eligible for an employer-subsidized plan through another job or a spouse.
  • Student loan interest, up to $2,500, phasing out at higher incomes.
  • Educator expenses for eligible K–12 teachers, up to $300 in unreimbursed classroom costs.7Internal Revenue Service. Topic No 458, Educator Expense Deduction
  • Early withdrawal penalties on time deposits like CDs cashed out before maturity.3Office of the Law Revision Counsel. 26 USC 62 – Adjusted Gross Income Defined

Subtract those adjustments from gross income, and the result is your AGI.

Why AGI Matters Beyond the Math

AGI isn’t just a step toward taxable income. It’s the figure the tax code uses throughout to decide whether you qualify for credits and deductions and how much of each you get. A lower AGI can unlock benefits that a higher AGI phases out.

The medical expense deduction is a plain example. You can deduct medical and dental costs only to the extent they exceed 7.5% of AGI.8Office of the Law Revision Counsel. 26 USC 213 – Medical, Dental, Etc., Expenses At $60,000 AGI, you need more than $4,500 in expenses before any deduction begins. Cut AGI to $50,000, and the floor drops to $3,750. Same expenses, larger deduction.

The Earned Income Tax Credit uses AGI for both eligibility and amount. For 2026, the maximum credit reaches $8,231 for families with three or more qualifying children and phases out entirely above roughly $63,000 for single filers or $70,000 for joint filers, depending on the number of children.9Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 The Child Tax Credit phases down by $50 for every $1,000 of AGI above the applicable threshold.

MAGI Is a Close Cousin

Many rules reference “modified adjusted gross income.” MAGI starts with AGI from line 11 and adds back certain items that were excluded or deducted, and the specific add-backs depend on which benefit is being tested.10Internal Revenue Service. Modified Adjusted Gross Income There is no universal MAGI formula.

For Roth IRA contributions in 2026, single filers with MAGI below $153,000 can contribute the full $7,500. The limit shrinks between $153,000 and $168,000 and disappears above that. Joint filers phase out between $242,000 and $252,000.4Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500 Common add-backs for MAGI calculations include foreign earned income excluded on Form 2555 and tax-exempt municipal bond interest. If your AGI sits close to a threshold, these can push you over.

How Taxable Income Is Calculated

Taxable income equals AGI minus another round of deductions, chiefly the standard deduction or itemized deductions, plus certain deductions available to non-itemizers.11Office of the Law Revision Counsel. 26 USC 63 – Taxable Income Defined

Standard Deduction

For 2026, the standard deduction is $16,100 for single and married-filing-separately filers, $32,200 for married filing jointly, and $24,150 for head of household.9Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Taxpayers 65 or older get an additional $6,000 deduction on top of those amounts, an enhanced provision in effect through 2028. A couple where both spouses are 65 or older can claim $12,000 in combined additional deductions.12Internal Revenue Service. Check Your Eligibility for the New Enhanced Deduction for Seniors A 67-year-old single filer’s effective standard deduction for 2026 is $22,100.

Itemized Deductions

If qualifying expenses on Schedule A exceed the standard deduction, itemizing saves more.13Internal Revenue Service. Instructions for Schedule A (Form 1040) The main ones:

  • State and local taxes, capped for most filers at approximately $40,000 ($20,000 if married filing separately), up from the $10,000 cap that applied through 2024. The cap phases down for filers with MAGI above roughly $500,000 but won’t drop below $10,000.
  • Mortgage interest on up to $750,000 of home acquisition debt ($375,000 if married filing separately).
  • Charitable contributions to qualified organizations, generally up to 60% of AGI for cash gifts.
  • Medical expenses above 7.5% of AGI.14Internal Revenue Service. Topic No 502, Medical and Dental Expenses

The higher SALT cap means more taxpayers in high-tax states will find that itemizing beats the standard deduction than in recent years. Run the numbers both ways if you own property and pay state income tax.

Qualified Business Income Deduction

If you earn income from a sole proprietorship, partnership, S corporation, or certain rental activities, the QBI deduction under Section 199A can knock up to 20% of qualified business income off taxable income, and it’s available even if you take the standard deduction.11Office of the Law Revision Counsel. 26 USC 63 – Taxable Income Defined For 2026, the full deduction is available without restriction when taxable income is below $201,750 ($403,500 for joint filers). Above those thresholds, additional limits kick in based on the type of business and the wages it pays.

How Brackets Apply to Taxable Income

Taxable income is what the rate schedule actually sees. Federal income tax is marginal: different slices of income are taxed at different rates. The 2026 brackets for single filers:9Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026

  • 10% on the first $12,400
  • 12% from $12,401 to $50,400
  • 22% from $50,401 to $105,700
  • 24% from $105,701 to $201,775
  • 32% from $201,776 to $256,225
  • 35% from $256,226 to $640,600
  • 37% above $640,600

For joint filers, each threshold is roughly double. A single filer with $56,900 in taxable income pays 10% on the first $12,400, 12% on the next $38,000, and 22% only on the last $6,500. The effective rate lands near 13%.

Because rates rise with income, deductions save the most when they cross a bracket line. A $1,000 deduction that pulls income from the 22% bracket into the 12% bracket saves $220. The same $1,000 entirely inside the 12% bracket saves $120.

The Three Numbers in a Single Example

Say you’re a single filer in 2026. You earn $85,000 in salary, $2,000 in bank interest, and $500 in dividends. Gross income: $87,500.

You contribute $4,400 to an HSA and $3,000 to a traditional IRA. Those above-the-line adjustments total $7,400, bringing AGI to $80,100. That’s the number the IRS uses to test your eligibility for credits and phase-outs.

Take the standard deduction of $16,100. Taxable income drops to $64,000. Tax on that: 10% on the first $12,400, 12% on the next $38,000, and 22% on the remaining $13,600, for roughly $9,812 before credits. A QBI deduction on any pass-through income would lower taxable income further.

Three numbers, each smaller than the last, each doing a different job. Gross income captures everything you received. AGI filters eligibility for benefits throughout the return. Taxable income sets the bill.