Your taxable income is not the same as your gross income, and that gap is where tax planning happens. Understanding what counts as taxable income — and what doesn’t — is the foundation of every legal strategy to reduce your tax bill.
What Is Taxable Income?
Taxable income is the portion of your income subject to federal income tax. It’s calculated by starting with your gross income, subtracting adjustments (called “above-the-line” deductions), arriving at Adjusted Gross Income (AGI), and then subtracting either the standard deduction or your itemized deductions. The result is your taxable income — the number the IRS applies your tax bracket to.
Formula: Gross Income − Adjustments = AGI − (Standard or Itemized Deductions) = Taxable Income
What Counts as Gross Income?
The IRS defines gross income as all income from any source unless specifically excluded. This includes:
- Wages, salaries, and tips
- Freelance and self-employment income
- Interest and dividends from investments
- Capital gains from selling investments or property
- Rental income
- Business income
- Alimony (for divorce agreements before 2019)
- Unemployment compensation
- Most Social Security benefits (if income exceeds certain thresholds)
What Is NOT Taxable Income?
Not everything you receive is taxable. Common exclusions:
- Employer-paid health insurance premiums
- Contributions to a health savings account (HSA) made by your employer
- Child support received
- Gifts (the giver may owe gift tax, but the recipient doesn’t owe income tax)
- Inheritances (in most cases)
- Life insurance death benefits received by beneficiaries
- Qualified Roth IRA withdrawals in retirement
- Workers’ compensation benefits
Above-the-Line Deductions That Reduce AGI
These deductions reduce your gross income before you reach AGI, and you can claim them whether or not you itemize. High-impact ones for 2026:
- 401(k) and traditional IRA contributions: Reduce taxable income dollar-for-dollar
- HSA contributions: Fully deductible up to the annual limit
- Student loan interest: Up to $2,500 deductible (income limits apply)
- Self-employment tax deduction: Deduct half of self-employment tax paid
- Self-employed health insurance: Premiums are deductible for self-employed individuals
- SEP IRA and Solo 401(k) contributions: Large deductions available for the self-employed
Standard Deduction vs. Itemized Deductions in 2026
After calculating your AGI, you choose between the standard deduction or itemizing. Take whichever is larger.
- Standard deduction (2026): $15,000 for single filers; $30,000 for married filing jointly
- Itemized deductions include: mortgage interest, state and local taxes (SALT, capped at $10,000), charitable contributions, and certain medical expenses exceeding 7.5% of AGI
The standard deduction is so large under current law that roughly 90% of filers take it. Itemizing generally only makes sense if you have a large mortgage, high state income taxes, and significant charitable giving.
How Tax Brackets Work on Taxable Income
A common misconception: if you’re in the 22% bracket, all of your income is taxed at 22%. That’s not how it works. Tax brackets are marginal — each bracket only applies to the income within that range.
For a single filer in 2026 with $75,000 of taxable income:
- First $11,925 taxed at 10%
- $11,926 to $48,475 taxed at 12%
- $48,476 to $75,000 taxed at 22%
Only the income above $48,475 is taxed at 22% — not the entire $75,000.
Practical Ways to Reduce Taxable Income
- Maximize pre-tax 401(k) contributions
- Contribute to a traditional IRA (if deductible)
- Fund an HSA to the annual limit
- Harvest investment losses to offset capital gains (tax-loss harvesting)
- Donate appreciated securities directly to charity instead of cash
- Time income recognition and deductions to concentrate them in the highest-income year
Related: What Is the Child Tax Credit? 2026 Guide
Related: What Is a Money Market Account?
Related: How to Open a Roth IRA: Step-by-Step Guide