Federal tax brackets are based on taxable income, not adjusted gross income. Taxable income is what remains after you subtract either the standard deduction or your itemized deductions from AGI, and it is the only figure the IRS runs through the seven bracket rates.
The Three Income Figures on Your Return
Your Form 1040 walks through income in a fixed order, and the brackets sit at the end of that walk. You start with gross income, everything you received during the year: wages, tips, interest, dividends, business profits, rental income, capital gains, retirement distributions, and other sources the tax code defines broadly as income “from whatever source derived.”1Office of the Law Revision Counsel. 26 USC 61 – Gross Income Defined
From gross income, you subtract above-the-line deductions to arrive at AGI. Then from AGI you subtract the standard deduction or your itemized deductions to arrive at taxable income. The bracket rates apply to that last figure.2Internal Revenue Service. Federal Income Tax Rates and Brackets
Above-the-line deductions appear on Schedule 1 before the AGI line and are available whether or not you itemize. Common ones include:
- Traditional IRA contributions, up to $7,500 for 2026, with the deductible amount phasing out at higher incomes if you or your spouse is covered by a workplace retirement plan.3Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026; IRA Limit Increases to $7,500
- Student loan interest, up to $2,500 a year.4Internal Revenue Service. Topic No. 456, Student Loan Interest Deduction
- Educator expenses, up to $300 for eligible teachers.5Internal Revenue Service. Topic No. 458, Educator Expense Deduction
- The deductible half of self-employment tax, and health insurance premiums for the self-employed.
- HSA contributions. The One, Big, Beautiful Bill expanded HSA access by making bronze and catastrophic health plans HSA-compatible starting in 2026.6Internal Revenue Service. One, Big, Beautiful Bill Provisions
Why AGI Still Matters
AGI doesn’t set your bracket, but it controls a lot of what happens elsewhere on the return. The Child Tax Credit begins to phase out once AGI exceeds $200,000 for single filers or $400,000 for married couples filing jointly.7Internal Revenue Service. Child Tax Credit The Earned Income Tax Credit, the Premium Tax Credit for marketplace health insurance, education credits, and the deductibility of traditional IRA contributions all hinge on AGI-based thresholds. A lower AGI can unlock benefits that a lower taxable income alone cannot.
Some provisions use Modified Adjusted Gross Income, which starts with AGI and adds back specific items like foreign earned income or tax-exempt interest. There is no single MAGI formula; the add-backs depend on which credit or deduction you’re calculating.8Internal Revenue Service. Modified Adjusted Gross Income Roth IRA contribution eligibility and the net investment income tax both use MAGI, so even taxpayers who never itemize may need to calculate it.
Getting From AGI to Taxable Income
To reach taxable income, you subtract whichever is larger: the standard deduction for your filing status, or the total of your itemized deductions.
Standard Deduction for 2026
Most filers take the standard deduction because it requires no documentation and provides a large, automatic reduction. For 2026:9Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments From the One, Big, Beautiful Bill
- Single or married filing separately: $16,100
- Married filing jointly: $32,200
- Head of household: $24,150
Filers age 65 or older get an additional deduction on top of those amounts. The One, Big, Beautiful Bill also created a new enhanced deduction for seniors of $4,000, available for 2025 through 2028, separate from the long-standing additional standard deduction for seniors. Personal exemptions remain at zero for 2026 after being permanently eliminated by the same bill.9Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments From the One, Big, Beautiful Bill
Itemized Deductions
You itemize when your qualifying expenses exceed the standard deduction. Itemized deductions are reported on Schedule A and include:10Internal Revenue Service. About Schedule A (Form 1040), Itemized Deductions
- State and local taxes (SALT). The One, Big, Beautiful Bill raised the SALT cap significantly. For 2025 the limit is $40,000 ($20,000 if married filing separately), phasing down for filers with modified AGI above $500,000 but never falling below $10,000. The cap is indexed for inflation, so the 2026 limit will be slightly higher.11Internal Revenue Service. Instructions for Schedule A (Form 1040) (2025)
- Mortgage interest on home acquisition debt, subject to loan-amount limits.
- Charitable contributions to qualifying organizations.
- Medical expenses exceeding 7.5% of AGI.
The QBI Deduction
If you earn income from a sole proprietorship, partnership, S corporation, or other pass-through business, you may qualify for the Section 199A deduction. The One, Big, Beautiful Bill made it permanent starting in 2026 and increased it from 20% to 23% of qualified business income. It is taken after AGI but sits outside Schedule A, so you can claim it alongside the standard deduction. It reduces taxable income directly, before brackets apply. Income limits and business-type restrictions determine whether you qualify for the full deduction or a reduced amount.
An Example That Shows Why the Distinction Matters
Consider a single filer in 2026 with an AGI of $60,000. That AGI sits inside the 22% bracket, which starts at $50,401 for single filers.9Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments From the One, Big, Beautiful Bill But brackets apply to taxable income. Subtract the $16,100 standard deduction and taxable income drops to $43,900, entirely within the 12% bracket. Applying bracket rates to AGI would overstate the tax bill.
For reference, the 2026 brackets for single filers are:
- 10% up to $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% over $640,600
Married filing jointly and head of household use the same seven rates against different income thresholds.
Marginal Rate vs. Effective Rate
Once you know brackets apply to taxable income, a second point follows. Every dollar of taxable income is taxed at the rate for the bracket it lands in, not at the rate of the highest bracket you reach. A single filer with $55,000 of taxable income doesn’t pay 22% on the whole amount. The first $12,400 is taxed at 10%, the next $38,000 at 12%, and only the remaining $4,600 at 22%. The total comes to about $7,429, an effective rate near 13.5%.
Your marginal rate is the rate on the last dollar you earned. Your effective rate is your total tax divided by your total income. The marginal rate answers what happens to the next dollar; the effective rate measures the overall burden. Effective rates run well below marginal rates for most taxpayers because of the layered brackets and the deductions that shrink income before any bracket touches it.
One Boundary: Long-Term Capital Gains
Long-term capital gains don’t use the seven ordinary-income brackets at all. Profits from investments held longer than one year run through a separate three-tier structure of 0%, 15%, and 20%, based on taxable income. For 2026, a single filer pays 0% on long-term gains if total taxable income stays below $49,450, 15% above that, and 20% once taxable income exceeds $545,500. Married couples filing jointly hit the 15% rate at $98,900 and the 20% rate at $613,700.12Tax Foundation. 2026 Tax Brackets and Federal Income Tax Rates Short-term gains on assets held one year or less get no preferential treatment; they’re added to ordinary income and taxed through the regular seven-bracket structure. High earners may also owe the 3.8% net investment income tax on top.