Tax deductions reduce the portion of your income the federal government can tax, which in turn lowers what you owe. For 2026, the standard deduction alone removes $16,100 from a single filer’s taxable income and $32,200 from a married couple filing jointly, before anyone looks at specific expenses like mortgage interest, state taxes, or charitable gifts. Beyond that flat amount, the tax code offers dozens of deductions aimed at homeowners, students, retirees, the self-employed, and people with large medical bills. Knowing which apply to you, and how much they’re actually worth, is the difference between paying what you owe and overpaying.
How a Deduction Lowers What You Owe
A deduction shrinks the income figure the IRS uses to calculate your tax. Earn $75,000, claim $16,100 in deductions, and you’re taxed on $58,900.1Internal Revenue Service. Credits and Deductions for Individuals The dollar savings depend on your tax bracket. A $2,000 deduction saves someone in the 24% bracket $480; the same $2,000 deduction saves someone in the 12% bracket only $240.
That’s what separates a deduction from a tax credit. A credit reduces your tax bill directly, dollar for dollar. A $1,000 credit takes $1,000 off what you owe regardless of your income. A $1,000 deduction only takes off a fraction, set by your top marginal rate. People mix these up all the time, and the confusion matters, because it changes how much any tax-driven financial decision is really worth.
The calculation runs in a set order. Start with gross income (wages, interest, dividends, and other earnings). Subtract certain “above-the-line” adjustments to get your adjusted gross income (AGI). Then subtract either the standard deduction or your itemized total to reach taxable income.2Office of the Law Revision Counsel. 26 USC 63 – Taxable Income Defined That final number is what the tax rates apply to.
The Standard Deduction or Itemizing
Every filer has one basic choice: take the flat standard deduction or list out specific expenses and add them up. For tax year 2026, the standard deduction amounts are:
- Single or married filing separately: $16,100
- Married filing jointly: $32,200
- Head of household: $24,150
Those figures reflect both inflation indexing and adjustments made by the One, Big, Beautiful Bill signed in 2025.3Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments From the One, Big, Beautiful Bill
Taxpayers age 65 or older already get a larger standard deduction under longstanding law. For 2025 through 2028, an enhanced deduction adds another $6,000 per qualifying individual on top of that. A married couple where both spouses are 65 or older can claim up to $12,000 in combined enhanced deductions on top of the regular standard deduction.4Internal Revenue Service. Check Your Eligibility for the New Enhanced Deduction for Seniors
A few filers can’t use the standard deduction at all. If your spouse itemizes and you file separately, you have to itemize too, even if the standard deduction would be higher for you. Nonresident aliens, anyone filing for a period shorter than 12 months because of an accounting change, and estates and trusts also can’t claim it.5Internal Revenue Service. Topic No. 551, Standard Deduction
When Itemizing Beats the Standard Deduction
Itemizing means listing every qualifying expense you actually paid during the year and adding them up. You only come out ahead if that total exceeds your standard deduction. Most filers don’t itemize because their standard deduction is higher than anything they could put on Schedule A. Homeowners with substantial mortgages, people who made large charitable gifts, or anyone with heavy medical bills in a single year are the ones who typically benefit.6Internal Revenue Service. Deductions for Individuals: What They Mean and the Difference Between Standard and Itemized Deductions
One planning move worth knowing is “bunching.” Instead of giving to charity evenly every year, you concentrate two or three years’ worth of donations into one year to push your itemized total above the standard deduction, then take the standard deduction in the off years. A couple who normally gives $10,000 a year could donate $30,000 in one year (through a donor-advised fund, for example), itemize that year, and take the standard deduction the next two. Over three years, the total deductions come out higher than giving $10,000 annually and never clearing the itemization line.
What People Actually Itemize
Mortgage Interest
Homeowners can deduct interest on mortgage debt used to buy, build, or substantially improve a primary or second home. The deduction covers interest on up to $750,000 of combined mortgage debt ($375,000 if married filing separately). Originally a temporary provision of the 2017 Tax Cuts and Jobs Act, this cap was made permanent by the One, Big, Beautiful Bill.7Office of the Law Revision Counsel. 26 USC 163 – Interest Mortgages taken out on or before December 15, 2017, still fall under the older $1 million limit.
Home equity loan or line-of-credit interest is deductible only if you used the borrowed money to improve the home securing the loan. Interest on a home equity line used to pay off credit cards or cover personal expenses is not deductible.8Internal Revenue Service. Real Estate (Taxes, Mortgage Interest, Points, Other Property Expenses) 2
State and Local Taxes
You can deduct state and local income taxes (or general sales taxes, but not both), plus property taxes. The combined cap is $40,000 for most filers ($20,000 if married filing separately), with a modified-AGI limitation that can reduce the cap but not below $10,000.9Internal Revenue Service. Topic No. 503, Deductible Taxes That’s a large increase from the flat $10,000 cap that applied from 2018 through 2024, and the cap adjusts annually for inflation through 2029.
Charitable Contributions
Cash or property given to qualified nonprofits is deductible if you itemize, with limits tied to a percentage of your AGI (generally 60% for cash gifts to public charities).10Office of the Law Revision Counsel. 26 USC 170 – Charitable, Etc., Contributions and Gifts Donated clothing and household goods must be in good used condition or better. There’s no fixed formula for valuing used items. The IRS expects you to use prices similar items actually sell for in thrift or consignment shops.11Internal Revenue Service. Publication 526, Charitable Contributions
Medical and Dental Expenses
Unreimbursed medical and dental expenses are deductible, but only the portion above 7.5% of your AGI. With an AGI of $80,000, the first $6,000 in medical costs gets you nothing; only dollars beyond that count.12Internal Revenue Service. Publication 502 (2025), Medical and Dental Expenses That floor is high enough that routine healthcare rarely qualifies.
When expenses do clear the threshold, the list of qualifying costs is broader than most people realize: prescription drugs, dental work, vision care, mental health treatment, transportation to medical appointments, and lodging (not meals) during out-of-town treatment at a licensed medical facility, capped at $50 per night per person.12Internal Revenue Service. Publication 502 (2025), Medical and Dental Expenses
Deductions You Can Claim Without Itemizing
Some deductions come out of your income before you make the standard-versus-itemized choice. These “above-the-line” adjustments reduce your AGI directly, which can also help you qualify for other tax benefits that phase out at higher income levels. You claim them on Schedule 1 of Form 1040 whether or not you itemize.
Student Loan Interest
Up to $2,500 in interest paid on qualified student loans is deductible.13Internal Revenue Service. Topic No. 456, Student Loan Interest Deduction For 2026, single filers begin to lose the deduction above $85,000 in modified AGI and lose it entirely at $100,000. Joint filers phase out between $175,000 and $205,000.
Educator Expenses
K–12 teachers and other eligible educators can deduct up to $350 in unreimbursed classroom supplies for 2026, up from $300 in prior years. You need to have worked at least 900 hours during the school year.
Health Savings Account Contributions
If you’re enrolled in a qualifying high-deductible health plan, HSA contributions are deductible above the line. For 2026, the limit is $4,400 for self-only coverage and $8,750 for family coverage.14Internal Revenue Service. Expanded Availability of Health Savings Accounts Under the One, Big, Beautiful Bill Act (OBBBA) – Notice 2026-5 Money goes in pre-tax, grows tax-free, and comes out tax-free when used for qualified medical expenses.
Traditional IRA Contributions
Contributions to a traditional IRA may be fully or partially deductible depending on your income and whether you or your spouse are covered by a workplace retirement plan. The 2026 contribution limit is $7,500. A single filer with a workplace plan starts phasing out at $81,000 in modified AGI and loses the deduction at $91,000. For a married couple filing jointly where the contributing spouse has a workplace plan, the range is $129,000 to $149,000.15Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500 If neither spouse has a workplace plan, the full contribution is deductible regardless of income.
Deductions for the Self-Employed
Self-employment opens up deductions that W-2 employees can’t take, and it also means no employer is tracking any of this for you. Missing these is one of the more expensive mistakes freelancers and small business owners make.
Self-employed workers pay both halves of Social Security and Medicare, which run 15.3% on net earnings combined. The deduction for the employer-equivalent half (7.65%) goes on Schedule 1, reducing AGI whether or not you itemize.
Premiums for medical, dental, and vision insurance covering yourself, a spouse, dependents, and children under 27 are 100% deductible above the line. The plan must be established under your business, and you can’t claim the deduction for any month you were eligible to participate in a subsidized plan through an employer or a spouse’s employer.16Internal Revenue Service. Instructions for Form 7206
If you use a dedicated space in your home exclusively and regularly as your principal place of business, you can deduct a portion of your housing costs. The word “exclusively” carries weight: a dining table that doubles as a workspace doesn’t qualify. Two methods are available. The actual-expense method calculates the business percentage of rent or mortgage interest, utilities, insurance, and depreciation. The simplified method uses $5 per square foot up to 300 square feet, capped at $1,500.17Internal Revenue Service. Publication 587 (2025), Business Use of Your Home
Ordinary business expenses reported on Schedule C are deductible, from software subscriptions and office supplies to advertising and professional services. For larger equipment purchases, the Section 179 deduction lets you write off the full cost in the year of purchase rather than depreciating it over years. The 2026 Section 179 maximum is $2,560,000, with a phase-out starting at $4,090,000 in total equipment purchases, ceilings most sole proprietors will never approach.
Records to Keep
Claiming a deduction without paperwork to support it invites trouble in an audit. The IRS doesn’t want receipts submitted with your return, but you need them on hand if questions come later.
- Mortgage interest: your lender sends Form 1098 each January, and Box 1 shows the interest paid.18Internal Revenue Service. Instructions for Form 1098
- Education expenses: schools issue Form 1098-T showing qualified tuition and related fees.19Internal Revenue Service. Form 1098-T 2025 Tuition Statement
- Charitable donations: cash gifts need a bank record or written receipt from the charity, and gifts of $250 or more require a written acknowledgment from the organization before you file.
- Medical expenses: keep receipts and explanation-of-benefits statements separately, so you can determine whether you clear the 7.5% AGI floor.
- Business and mileage expenses: a contemporaneous log with dates, destinations, and business purpose is far more persuasive to an auditor than a reconstructed estimate.
Digital copies are fine as long as they’re legible, retrievable, and protected against alteration. Keep all supporting records for at least three years after the date you file, or two years after you pay the tax, whichever is later.20Internal Revenue Service. How Long Should I Keep Records? If you substantially underreport income, the IRS has six years. For a fraudulent return, there’s no time limit.21Internal Revenue Service. Time IRS Can Assess Tax
Where Deductions Go on the Return
Everything flows through Form 1040.22Internal Revenue Service. About Form 1040, U.S. Individual Income Tax Return Above-the-line deductions go on Schedule 1. If you itemize, you also fill out Schedule A, which sorts your expenses into categories: medical, taxes, interest, charitable contributions, and other deductions.23Internal Revenue Service. About Schedule A (Form 1040), Itemized Deductions Take the standard deduction and Schedule A stays blank.
What Happens If You Claim Something You Shouldn’t
Honest mistakes on deductions happen, but the IRS separates carelessness from fraud, and the penalties reflect that.
An underpayment caused by negligence or a substantial understatement of tax triggers an accuracy-related penalty of 20% of the underpaid amount. For individuals, “substantial understatement” means the shortfall is more than the greater of 10% of the tax that should have been reported or $5,000.24Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments Inflate a charitable deduction by a few thousand dollars, get caught, and you owe the missing tax plus 20% on top.
Intentional fraud carries a 75% penalty on the portion of the underpayment attributable to fraud, and there’s no time limit on how far back the IRS can go to assess it.21Internal Revenue Service. Time IRS Can Assess Tax Protection against both is simple: claim only deductions you can document, use realistic valuations for donated property, and keep your records for at least three years after filing.