Tax Deduction
Quick Definition
A tax deduction is an expense or allowance that reduces your taxable income, thereby reducing the amount of income subject to federal income tax. The tax savings from a deduction equals the deduction amount multiplied by your marginal tax bracket rate. A $1,000 deduction for a 22% bracket taxpayer saves $220 in taxes.
Tax Saved by Deduction = Deduction Amount x Marginal Tax Rate
What It Means
Tax deductions are one of the primary mechanisms through which the tax code encourages certain behaviors (homeownership, charitable giving, retirement saving, healthcare spending) and provides relief for unavoidable expenses (medical costs, state taxes).
Unlike a tax credit, which reduces taxes dollar-for-dollar, a deduction reduces taxable income. The tax savings depend on your bracket. This makes deductions more valuable to high earners (who save more per dollar deducted) and less valuable to lower earners.
The One Big Beautiful Bill Act (OBBBA), signed July 4, 2025, made the elevated standard deduction permanent and introduced several new deduction provisions that take effect for 2025-2026.
Types of Tax Deductions
Above-the-Line Deductions (Before AGI)
These reduce AGI directly and can be claimed regardless of whether you take the standard deduction. They are the most universally accessible:
| Deduction | 2026 Limit | Who Qualifies |
|---|---|---|
| Traditional IRA contribution | $7,500 ($8,600 if 50+) | Within income limits |
| 401(k)/403(b)/457 (reduces W-2) | $24,500 ($32,500 if 50+) | Employees with workplace plans |
| HSA contribution | $4,400 self-only / $8,750 family | HDHP health plan enrollees |
| Self-employed health insurance | Actual premium | Self-employed only |
| SEP IRA contribution | Up to $70,000 (2026 est.) | Self-employed only |
| Student loan interest | Up to $2,500 | Income phase-out applies |
| Educator expenses | Up to $300 | K-12 teachers |
| Overtime pay deduction | Up to $12,500 (single) / $25,000 (MFJ) | New OBBBA provision for non-exempt workers |
| Car loan interest | Up to $10,000 | New OBBBA provision, income limits apply |
The overtime pay deduction and car loan interest deduction are new OBBBA provisions effective starting in 2025. The overtime deduction allows eligible non-exempt workers to deduct a portion of overtime pay from gross income, before AGI is calculated.
Below-the-Line (Itemized) Deductions
These replace the standard deduction if their total exceeds it:
| Deduction | 2026 Limit |
|---|---|
| State and local taxes (SALT) | $40,400 cap ($20,200 MFS), phasing down above $505,000 MAGI |
| Mortgage interest | On first $750,000 of acquisition debt |
| Charitable contributions (cash) | Up to 60% of AGI |
| Charitable contributions (property) | Up to 30% of AGI |
| Medical expenses | Exceeding 7.5% of AGI |
| Gambling losses | Up to gambling winnings |
| Casualty losses | Federally declared disasters only |
The SALT Cap: Major OBBBA Change
The OBBBA raised the SALT deduction cap from $10,000 to $40,000 for 2025, with a 1% annual increase built into the statute. For 2026, the cap is $40,400 ($20,200 for married filing separately).
The enhanced cap phases down for high earners:
- Phase-out begins at $505,000 MAGI ($252,500 MFS) for 2026
- The cap is reduced by 30% of MAGI above the threshold
- The cap cannot drop below $10,000 ($5,000 MFS)
This is a temporary provision: the enhanced cap applies 2025 through 2029, then reverts to $10,000 in 2030 unless Congress acts again.
For a retired couple in New York paying $18,000 in state income tax and $22,000 in property tax, the full $40,400 can now be deducted instead of being capped at $10,000. This significantly changes the itemize-vs-standard-deduction calculus for many households in high-tax states.
The Standard Deduction (2026)
The OBBBA made the elevated standard deduction permanent, removing the scheduled 2026 sunset:
| Filing Status | 2026 Standard Deduction |
|---|---|
| Single | $16,100 |
| Married Filing Jointly | $32,200 |
| Head of Household | $24,150 |
| Married Filing Separately | $16,100 |
| Qualifying Surviving Spouse | $32,200 |
Additional amounts for age 65+ or blind (2026): $2,050 for single/head of household; $1,650 per person for married filers. A married couple where both spouses are 65+ can claim $32,200 + $1,650 + $1,650 = $35,500.
Senior Bonus Deduction (New OBBBA Provision)
The OBBBA introduced a temporary additional deduction of $6,000 per person ($12,000 for married couples) for taxpayers 65 and older, available 2025 through 2028. It phases out at $75,000 MAGI (single) or $150,000 (MFJ). This is on top of the existing extra standard deduction for seniors.
Charitable Deduction for Non-Itemizers (New for 2026)
Starting in 2026, the OBBBA allows non-itemizers to deduct $1,000 (single) or $2,000 (MFJ) for charitable contributions above the line. Itemizers must surpass 0.5% of AGI to deduct additional giving, and the value is capped at 35% of AGI.
Approximately 90% of taxpayers take the standard deduction. For most of them, charitable contributions provided no tax benefit under prior law. This new provision restores a modest charitable deduction for standard-deduction filers.
Tax Deduction vs. Tax Credit: The Critical Difference
| Feature | Tax Deduction | Tax Credit |
|---|---|---|
| What it reduces | Taxable income | Tax owed |
| Value at 22% bracket | $220 per $1,000 | $1,000 per $1,000 |
| Value at 12% bracket | $120 per $1,000 | $1,000 per $1,000 |
| Value at 37% bracket | $370 per $1,000 | $1,000 per $1,000 |
| Dependent on bracket? | Yes | No |
Credits are always more valuable than equivalent deductions. A $2,200 child tax credit saves $2,200 in taxes regardless of bracket. A $2,200 deduction saves $264 to $814 depending on your marginal rate.
Calculating the Value of a Deduction
Example: You are in the 24% tax bracket and can claim $18,000 in itemized deductions (vs. the $16,100 standard deduction for a single filer in 2026).
- Standard deduction: $16,100
- Itemized deductions: $18,000
- Excess over standard: $1,900
- Tax savings from itemizing: $1,900 x 24% = $456
You only benefit from itemized deductions on the amount that exceeds the standard deduction. With the OBBBA's higher SALT cap, more filers in high-tax states will find itemizing worthwhile for the first time since 2018.
Bunching Deductions: A Powerful Strategy
If your itemized deductions are close to but not exceeding the standard deduction, consider "bunching": concentrating deductions into alternating years.
Example: $14,000/year in potential itemized deductions (less than $16,100 standard for single in 2026):
- Year 1: Donate $4,000 (total $18,000 itemized). Itemize, saving over $16,100.
- Year 2: Donate $0 (total $14,000 itemized). Take standard deduction.
- Vs. donating $2,000 each year: Always take standard; no extra benefit.
Using a Donor-Advised Fund (DAF) is ideal for this: make 2 years of charitable contributions in one year, take the large deduction, then distribute grants from the DAF to charities over the following years.
Business Deductions: Reducing Self-Employment Income
Self-employed individuals and small business owners have extensive deduction opportunities:
| Business Deduction | Notes |
|---|---|
| Home office | Regular, exclusive business use; $5/sq ft simplified or actual expenses |
| Vehicle (business use) | Standard mileage rate or actual costs |
| Business travel | Airfare, lodging, 50% of meals |
| Professional development | Business-related courses, books, subscriptions |
| Marketing and advertising | Business-related only |
| Health insurance premiums | Above-the-line for self-employed |
| Retirement plan contributions | SEP IRA, Solo 401(k) up to $70,000 (2026 est.) |
| Section 179 / bonus depreciation | Immediate expensing of equipment purchases |
| Qualified Business Income (QBI) | 20% deduction on pass-through income, made permanent by OBBBA |
The QBI deduction, which allows pass-through business owners to deduct 20% of qualified business income, was made permanent by the OBBBA. This is one of the most valuable deductions for self-employed individuals and small business owners.
Key Points to Remember
- A deduction reduces taxable income. The actual tax saved equals deduction x marginal rate.
- The 2026 standard deduction is $16,100 (single) / $32,200 (MFJ), made permanent by the OBBBA.
- The SALT cap rose to $40,400 for 2026, up from $10,000 under prior law. It phases down above $505,000 MAGI and reverts to $10,000 in 2030.
- New OBBBA provisions for 2026: senior bonus deduction ($6,000 per person 65+), charitable deduction for non-itemizers ($1,000/$2,000), overtime pay deduction, and car loan interest deduction.
- Tax credits are more valuable than deductions. They reduce tax owed dollar-for-dollar.
- Bunching deductions into alternating years can unlock itemized deduction benefits.
- The QBI deduction (20% of pass-through business income) is now permanent.
Common Mistakes to Avoid
- Confusing deductions with credits: A $5,000 deduction at 22% saves $1,100. A $5,000 credit saves $5,000.
- Not tracking charitable contributions: Cash donations under $250 require a receipt; over $250 require written acknowledgment from the charity. The new non-itemizer charitable deduction makes tracking even more important.
- Missing above-the-line deductions: HSA contributions ($4,400/$8,750 in 2026), student loan interest, IRA contributions, and the new overtime deduction reduce AGI regardless of whether you itemize.
- Ignoring the SALT phase-out: If your MAGI is above $505,000, the $40,400 cap phases down. High earners in high-tax states may still effectively hit the $10,000 floor.
- Assuming you should itemize because you always have: With the higher standard deduction and the new SALT cap, run the numbers each year. The OBBBA changes shift the break-even point for many filers.
Related Concepts
- Tax Credit: Reduces tax owed directly, always more valuable than a deduction
- Tax Bracket: Determines how much each dollar of deduction is worth
- Taxable Income: What deductions reduce before tax rates apply
- Adjusted Gross Income (AGI): The income figure after above-the-line deductions
- Standard Deduction: The flat amount available to all non-itemizing filers
- Capital Gains: Taxed at separate rates, but losses can be deducted (up to $3,000/year)
For tax-loss harvesting strategies that use investment losses as deductions, read our guide on tax-loss harvesting. To estimate your tax liability with different deduction scenarios, use our tax bracket calculator.
Frequently Asked Questions
Q: Should I always itemize if I can? A: Only itemize if your total qualifying deductions exceed the standard deduction for your filing status. For 2026, the standard deduction is $16,100 (single) or $32,200 (MFJ). With the OBBBA's higher SALT cap ($40,400), more filers in high-tax states will benefit from itemizing than in recent years. Run the numbers each year.
Q: Can I deduct my home office if I work from home for an employer? A: No. The 2017 Tax Cuts and Jobs Act eliminated the home office deduction for W-2 employees. Only self-employed individuals (Schedule C) and certain other categories can deduct home office expenses.
Q: What is the SALT deduction cap for 2026? A: The OBBBA raised the SALT cap to $40,400 for 2026 ($20,200 for married filing separately). It phases down by 30% of MAGI above $505,000 ($252,500 MFS), but cannot drop below $10,000. This enhanced cap is temporary: it applies 2025 through 2029 and reverts to $10,000 in 2030.
Q: What happens if I overstate my deductions? A: Claiming false or inflated deductions is tax fraud. The IRS can audit returns up to 3 years after filing (6 years if significant income is omitted). Penalties include repayment of taxes owed, interest, and accuracy penalties of 20-25% of the underpayment. Intentional fraud carries criminal penalties including fines and imprisonment.
