Every deduction on a federal return sits on one side of a single line, and the side determines whether it helps you. Above-the-line vs. below-the-line tax deductions is really a question about Adjusted Gross Income: above-the-line deductions come off your income before AGI is calculated and are available to everyone who qualifies, while below-the-line deductions come after AGI and only matter if your itemized total beats the standard deduction. For 2026, the standard deduction is $16,100 for single filers and $32,200 for married couples filing jointly, so clearing that bar takes real expenses.1Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
Why the Line Matters
The “line” is Adjusted Gross Income, the figure that appears on Form 1040 after you subtract above-the-line adjustments from gross income. AGI acts as a gatekeeper for the rest of the return. A lower AGI can qualify you for larger credits, let you deduct more of your medical bills, keep you under phase-out thresholds for education benefits, and influence your capital gains tax rate. Two taxpayers with identical gross income can end up with very different tax bills depending on how well they manage AGI.
Below-the-line deductions, by contrast, are an either/or choice. You either take the flat standard deduction or itemize on Schedule A, whichever is larger. You cannot do both, and you cannot pick individual itemized deductions to stack on top of the standard amount. Roughly 90% of taxpayers now take the standard deduction because the amount is high enough that itemizing rarely wins.
Above-the-Line Deductions Anyone Who Qualifies Can Take
Above-the-line deductions are reported on Schedule 1 of Form 1040 and often called “adjustments to income.” Every dollar you claim reduces AGI directly, which ripples through the rest of the return.
Retirement and Health Savings Contributions
Traditional IRA contributions are among the most common. For 2026, you can contribute up to $7,500, or $8,600 if you’re 50 or older, though income limits may reduce or eliminate the deduction if you or your spouse is covered by a workplace retirement plan.2Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,5003Internal Revenue Service. Publication 590-A, Contributions to Individual Retirement Arrangements
Health Savings Account contributions carry a stronger benefit. With a qualifying high-deductible health plan, the money goes in tax-free, grows tax-free, and comes out tax-free when spent on medical expenses. The 2026 limits are $4,400 for self-only coverage and $8,750 for family coverage.4Internal Revenue Service. Notice 26-05: HSA Inflation Adjusted Amounts for 2026
Self-Employment Adjustments
If you’re self-employed, you can deduct the employer-equivalent half of your self-employment tax as an above-the-line adjustment. The deduction does not reduce the self-employment tax itself, but it lowers the income used to calculate your regular income tax.5Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes) You can also deduct health insurance premiums paid for yourself, your spouse, and your dependents, provided you weren’t eligible for an employer-sponsored plan.
Student Loan Interest
Student loan interest is deductible up to $2,500 per year without itemizing.6Internal Revenue Service. Topic No. 456, Student Loan Interest Deduction The deduction phases out at higher incomes, so it mostly reaches borrowers in early and mid-career.
Two Boundaries Worth Knowing
Alimony is deductible above the line only if the divorce or separation agreement was executed before 2019. Agreements finalized after December 31, 2018 don’t qualify, and older agreements modified to adopt the newer rules lose the deduction as well.7Internal Revenue Service. Topic No. 452, Alimony and Separate Maintenance
Moving expenses used to be deductible above the line, but since 2018 the deduction has been limited to active-duty members of the Armed Forces who relocate due to a permanent change of station. Civilians no longer qualify.
The Standard Deduction You Have to Beat
Before any below-the-line deduction helps, your itemized total has to clear the standard deduction. For 2026:
- Single or married filing separately: $16,100
- Married filing jointly or surviving spouse: $32,200
- Head of household: $24,150
These amounts reflect inflation-adjusted figures under the One Big Beautiful Bill Act (OBBB), signed in mid-2025, which made the higher standard deduction permanent.1Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
Taxpayers 65 or older get an additional boost. The OBBB created a new senior deduction of $4,000 per qualifying individual for tax years 2025 through 2028, on top of the existing additional standard deduction for age and blindness.8Internal Revenue Service. 2026 Filing Season Updates and Resources for Seniors A married couple where both spouses are 65 or older can claim up to $8,000 in combined additional senior deductions under this new provision alone.
Below-the-Line Deductions That Can Clear the Bar
If you decide to itemize, you report the deductions on Schedule A.9Internal Revenue Service. About Schedule A (Form 1040), Itemized Deductions The deductions below are the ones that typically add up to enough to matter.
State and Local Taxes (SALT)
The SALT deduction covers property taxes plus either state income taxes or state sales taxes, whichever saves you more. Under the OBBB, the cap increased to $40,000 for 2026 ($20,000 for married filing separately), a significant jump from the $10,000 cap that applied from 2018 through 2024. The cap phases down for taxpayers with modified AGI above $500,000, with the deduction reduced by 30 cents for every dollar above that threshold. Taxpayers with modified AGI at or above $600,000 fall back to the old $10,000 limit.
Mortgage Interest
Interest on mortgage debt used to buy or substantially improve your home is deductible if you itemize. For loans taken out after December 15, 2017, the deduction applies to the first $750,000 of mortgage debt ($375,000 if married filing separately). Older loans are grandfathered under the previous $1 million limit.10Congress.gov. Reforms to the Mortgage Interest Deduction with Revenue Estimates The OBBB made the $750,000 threshold permanent for post-2017 mortgages.
Medical and Dental Expenses
Unreimbursed medical and dental expenses are deductible, but only the portion that exceeds 7.5% of your AGI.11Internal Revenue Service. Publication 502, Medical and Dental Expenses Someone with an AGI of $80,000 would need more than $6,000 in unreimbursed costs before a single dollar becomes deductible. This one usually matters in years with major surgeries, extended hospital stays, or expensive dental work.
Charitable Contributions
Cash donations to public charities are deductible up to 60% of AGI.12Internal Revenue Service. Publication 526, Charitable Contributions Donations of appreciated property, contributions to private foundations, and gifts to certain other organizations face lower limits of 20% or 30% of AGI. Any excess carries forward for up to five years. Get a written acknowledgment from the charity for any single gift of $250 or more.
What Was Cut, and What Moved
Before 2018, taxpayers who itemized could deduct tax preparation fees, unreimbursed employee business expenses, investment advisory fees, and other miscellaneous costs that collectively exceeded 2% of AGI. The TCJA suspended these, and the OBBB made that suspension permanent.
The educator expense deduction has shifted sides of the line. Through 2025, teachers could deduct up to $300 of unreimbursed classroom costs ($600 for two married educators) as an above-the-line adjustment.13Internal Revenue Service. Topic No. 458, Educator Expense Deduction Starting in 2026, the OBBB removed the dollar cap but moved the deduction to Schedule A. Only educators who itemize will benefit; the majority who take the standard deduction lose this break entirely.
How the Two Sides Interact
Above-the-line and below-the-line deductions aren’t independent. Lower your AGI by $10,000 through IRA and HSA contributions, and the 7.5% medical expense floor drops by $750. More of your medical bills become deductible below the line as a result. Above-the-line deductions also protect credits and rates that key off AGI.
The Child Tax Credit for 2026 is worth up to $2,200 per qualifying child under 17, with up to $1,700 available as a refund. The full credit is available to single filers with AGI up to $200,000 and married couples filing jointly up to $400,000, after which it phases down.14Internal Revenue Service. Child Tax Credit The Earned Income Tax Credit uses both earned income and AGI to determine eligibility and credit size, with a 2026 maximum of $8,231 for a family with three or more children.1Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
The 3.8% Net Investment Income Tax kicks in when modified AGI exceeds $200,000 (single) or $250,000 (married filing jointly).15Internal Revenue Service. Topic No. 559, Net Investment Income Tax A well-timed IRA or HSA contribution can push you below that threshold and avoid the surcharge. Long-term capital gains rates also flow from taxable income, so a lower AGI can keep gains in the 0% bracket.16Internal Revenue Service. Topic No. 409, Capital Gains and Losses
Records to Keep
Every deduction needs documentation. Keep records supporting any deduction for at least three years from the date you filed the return.17Internal Revenue Service. How Long Should I Keep Records For above-the-line deductions, the paperwork largely arrives on its own: your IRA custodian sends Form 5498, your HSA administrator sends Form 5498-SA, and your student loan servicer sends Form 1098-E. Itemized deductions require more active record-keeping. Save property tax bills, state tax returns, medical receipts, mortgage interest statements (Form 1098), and charity acknowledgment letters.