What Is a Tax Deduction? Definition, Types, Examples
Last updated 04/07/2026 by
Ante Mazalin
Edited by
Andrew Latham
Summary:
A tax deduction is an expense you subtract from your gross income to reduce the amount of income subject to taxation, lowering your overall tax bill.
Deductions fall into two main categories based on how you claim them.
- Standard deduction: A flat dollar amount the IRS allows you to subtract based on your filing status — no receipts or itemizing required. For 2024, it’s $14,600 for single filers and $29,200 for married filing jointly.
- Itemized deductions: Individual expenses you list on Schedule A — mortgage interest, state and local taxes (SALT), charitable contributions, and qualifying medical costs. Worth claiming only if total itemized deductions exceed your standard deduction.
- Above-the-line deductions: Also called “adjustments to income,” these are deductible regardless of whether you itemize — including student loan interest, IRA contributions, and health savings account (HSA) contributions.
A tax deduction isn’t a dollar-for-dollar reduction in what you owe — it reduces your taxable income, and the actual tax savings depend on your marginal tax bracket. Understanding this distinction helps you accurately assess whether a deduction is worth pursuing.
How Tax Deductions Work
The math is straightforward: if you earn $70,000 and claim $14,600 in standard deductions, your taxable income drops to $55,400. You pay tax only on $55,400, not $70,000.
The actual dollar value of a deduction depends on your tax bracket. The same $1,000 deduction saves $120 for someone in the 12% bracket and $370 for someone in the 37% bracket — deductions are more valuable at higher income levels.
| Tax Bracket | Value of $1,000 Deduction |
|---|---|
| 10% | $100 |
| 12% | $120 |
| 22% | $220 |
| 24% | $240 |
| 32% | $320 |
| 35% | $350 |
| 37% | $370 |
Standard Deduction vs. Itemized Deductions
The choice between standard and itemized deductions is simply math: take whichever is larger. About 90% of taxpayers take the standard deduction, according to IRS data — the 2017 Tax Cuts and Jobs Act roughly doubled standard deduction amounts, making itemizing less advantageous for most filers.
If you’re unsure which to choose, see when it makes sense to itemize.
2024 and 2025 standard deduction amounts:
| Filing Status | 2024 | 2025 |
|---|---|---|
| Single / Married Filing Separately | $14,600 | $15,000 |
| Married Filing Jointly / Qualifying Widow(er) | $29,200 | $30,000 |
| Head of Household | $21,900 | $22,500 |
Taxpayers 65 or older (or blind) receive an additional standard deduction amount: $1,950 for single filers and $1,550 for each eligible spouse in 2024.
Common Itemized Deductions
If your total eligible expenses exceed your standard deduction, itemizing on Schedule A is the better choice. The most significant itemized deductions include:
- Mortgage interest: Interest paid on up to $750,000 of mortgage debt on a primary or secondary home ($1 million for mortgages originated before December 15, 2017).
- State and local taxes (SALT): Property taxes plus either state income tax or sales tax — capped at $10,000 per return ($5,000 for married filing separately) under current law.
- Charitable contributions: Cash donations up to 60% of AGI; appreciated stock donations up to 30% of AGI. Requires written acknowledgment from the organization for donations of $250 or more.
- Medical and dental expenses: Qualifying costs exceeding 7.5% of adjusted gross income (AGI). Only the amount above that threshold is deductible.
- Casualty and theft losses: Only for losses from federally declared disasters under current law.
Above-the-Line Deductions (Available Without Itemizing)
Above-the-line deductions reduce your AGI regardless of whether you itemize — making them universally valuable. Key examples:
- Traditional IRA contributions: Up to $7,000 ($8,000 if 50+) in 2024, subject to income limits if covered by a workplace plan.
- Health Savings Account (HSA) contributions: Up to $4,150 (individual) or $8,300 (family) in 2024.
- Student loan interest: Up to $2,500, subject to income phase-outs.
- Self-employment tax: 50% of self-employment tax paid.
- Self-employed health insurance premiums: 100% of premiums for self-employed individuals.
- Educator expenses: Up to $300 for classroom supplies paid out-of-pocket.
- Alimony paid under pre-2019 divorce agreements.
Pro Tip: “Bunching” is a strategy where you alternate between itemizing and taking the standard deduction by concentrating deductible expenses into every other year. In a bunching year, you pre-pay property taxes, make two years of charitable donations, and accelerate other deductible expenses — pushing your total above the standard deduction threshold. In off years, you take the standard deduction. This can generate more total tax savings than claiming the same expenses every year.
Key takeaways
- A tax deduction reduces your taxable income — not your tax bill directly. The actual savings depend on your marginal bracket.
- About 90% of taxpayers take the standard deduction. Itemizing only makes sense if your total qualifying expenses exceed the standard deduction for your filing status.
- Above-the-line deductions (IRA contributions, HSA contributions, student loan interest) are available regardless of whether you itemize.
- Deductions are worth more at higher tax brackets — a $1,000 deduction saves $370 in the 37% bracket versus $100 in the 10% bracket.
- The “bunching” strategy can amplify deduction value by concentrating itemizable expenses into alternating years.
Frequently Asked Questions
What is the difference between a tax deduction and a tax credit?
A deduction reduces your taxable income; a tax credit reduces your actual tax bill dollar-for-dollar. A $1,000 credit always saves $1,000. A $1,000 deduction saves between $100 and $370 depending on your bracket — making credits more valuable in most cases.
What is an above-the-line deduction?
Above-the-line deductions (formally “adjustments to income”) are subtracted from gross income to arrive at adjusted gross income (AGI), regardless of whether you itemize. They include IRA contributions, HSA contributions, student loan interest, and self-employment tax. They’re called “above the line” because AGI is the line on the tax form — these come before it.
Do tax deductions expire?
Some deductions have built-in expiration dates. Several provisions of the 2017 Tax Cuts and Jobs Act are set to expire after 2025, including the increased standard deduction amounts and the $10,000 SALT cap. Congress must act to extend them, which has been an ongoing legislative debate. For a complete breakdown of what you can deduct, see the full tax deduction guide.
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