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TaxWren
Next IRS deadline:Extended 2025 tax returns due ·

2026 tax year · updated

Tax glossary

55 US tax terms you meet on a paycheck, a tax form or in our calculators, each explained in a sentence or two with this year's figures and a link to the official source.

Explained in depth

A

3 terms

Deductions

Above-the-line deduction (adjustment to income)

A deduction subtracted from gross income to reach adjusted gross income (an adjustment to income on Schedule 1), so you get it whether or not you itemize. Examples: deductible IRA and HSA contributions, student loan interest, the deductible part of self-employment tax.

Source

See also: Adjusted gross income

Payroll and self-employment

Additional Medicare tax

An extra 0.9% Medicare tax on wages and self-employment income above $200,000 ($250,000 married filing jointly).

Source

See also: FICA

C

2 terms

D

1 term

Filing

Dependent

A qualifying child or qualifying relative you can claim on your return, which can bring credits such as the child tax credit. A qualifying relative generally can't have gross income of $5,200 or more (2025).

Source

See also: Head of household, Child tax credit, Unearned income

E

4 terms

Income

Earned income

Pay for work you actually do: salaries, wages, tips, professional fees and other amounts received for services. Interest, dividends, pensions and Social Security are not earned income.

Source

See also: Unearned income, Earned income credit

Credits

Earned income credit (EITC, EIC)

A refundable credit for workers with low to moderate earned income; the amount depends on income, filing status and the number of qualifying children. You must file a return to get it, even if you aren't otherwise required to file.

Source

See also: Earned income, Refundable tax credit

F

8 terms

Filing

Filing requirement (filing threshold)

The income at which you must file a federal return. For 2025 it is $15,750 of gross income for a single filer under 65 and $31,500 for a married couple filing jointly; $400 of net self-employment earnings always requires a return.

Do I need to file taxes?Source

See also: Gross income, Dependent

Forms

Form 1040

The US individual income tax return, where you report the year's income, deductions and credits and figure your tax, refund or balance due.

Source

See also: Adjusted gross income, Taxable income

Forms

Form 1099-K

A form from payment apps and online marketplaces reporting payments you received for goods or services. They must send one when your payments are over $20,000 and number more than 200, but the income is taxable whether or not you get a form.

Source

See also: Form 1099-NEC

Forms

Form W-2 (Wage and Tax Statement)

The form your employer gives you showing your wages for the year and the federal, state, Social Security and Medicare taxes withheld from them.

Source

See also: W-2 vs. 1099, Withholding

Forms

Form W-4

The form you give your employer to tell it how much federal income tax to withhold from your pay.

Source

See also: Withholding

G

2 terms

H

1 term

I

1 term

Deductions

Itemized deductions

Specific expenses you can deduct on Schedule A instead of taking the standard deduction: state and local taxes (up to $40,400 in 2026), home mortgage interest, gifts to charity and medical expenses above 7.5% of AGI, among others. You itemize only when they add up to more than your standard deduction.

Source

See also: Standard vs. itemized deductions, SALT deduction, Standard deduction

M

4 terms

Filing

Married filing jointly (MFJ)

One return for a married couple, combining both spouses' income and deductions. It often gives a lower tax than filing separately, and both spouses are responsible for the tax on it.

Source

See also: Filing status, Married filing separately

Filing

Married filing separately (MFS)

Each spouse files a return with their own income and deductions. The tax is usually higher than on a joint return and some credits are limited or not allowed, but each spouse is responsible only for their own return.

Source

See also: Filing status, Married filing jointly

N

2 terms

P

2 terms

Rates and brackets

Progressive tax

A tax whose rate rises with income, like the federal income tax: each bracket's rate applies only to the income within it.

Source

See also: Tax bracket

State and local

Property tax

A tax on the value of real estate, set by counties, cities and school districts. The median US homeowner pays $3,211 a year, an effective rate of 0.89% of home value.

Property tax calculatorSource

See also: SALT deduction

Q

3 terms

Deductions

Qualified business income deduction (QBI deduction, Section 199A)

A deduction of up to 20% of qualified business income from a sole proprietorship, partnership or S corporation, taken whether or not you itemize. Extra limits apply once taxable income passes $201,750 ($403,500 joint) in 2026.

1099 tax calculatorSource

See also: Taxable income, Self-employment tax

Investing and retirement

Qualified dividends

Dividends taxed at the lower long-term capital gains rates instead of ordinary rates, reported in box 1b of Form 1099-DIV. You must have held the stock for more than 60 days in the 121-day period around the ex-dividend date.

Capital gains and dividend tax calculatorSource

See also: Capital gain

Filing

Qualifying surviving spouse (qualifying widow(er))

A filing status for the two years after the year your spouse died, if you have a dependent child living with you and meet the other tests. It uses the married filing jointly brackets and standard deduction.

Source

See also: Filing status

R

3 terms

Investing and retirement

Required minimum distribution (RMD)

The amount you must withdraw each year from a traditional IRA starting with the year you turn 73, figured from your December 31 balance and an IRS life expectancy table.

RMD calculatorSource

See also: Roth conversion

S

9 terms

State and local

Sales tax

A tax on retail purchases charged by states and local governments and added at the register. 5 states have no statewide sales tax. If you itemize, you can deduct sales tax instead of state income tax.

Sales tax calculatorSource

See also: SALT deduction

Deductions

SALT deduction (state and local tax deduction)

The itemized deduction for state and local taxes: state income tax (or sales tax) plus property taxes. For 2026 it is capped at $40,400 ($20,200 married filing separately), reduced by 30% of modified AGI over $505,000 but not below $10,000.

Property tax calculatorSource

See also: Itemized deductions, Property tax

Deductions

Senior deduction (bonus deduction for seniors)

An extra deduction of up to $6,000 for each person 65 or older, for tax years 2025 to 2028, on top of the standard or itemized deductions. It shrinks by 6% of modified AGI over $75,000 ($150,000 joint).

Source

See also: Standard deduction, Modified adjusted gross income

Filing

Substantial presence test

The day-count test that makes a non-citizen without a green card a US resident for tax purposes: at least 31 days in the US this year and 183 days over three years, counting all of this year's days, a third of last year's and a sixth of the year before.

Substantial presence test calculatorSource

See also: Filing requirement

T

6 terms

Filing

Tax extension (Form 4868)

An automatic 6-month extension of the time to file, requested on Form 4868 by the filing deadline. It doesn't extend the time to pay: tax owed is still due by the original deadline.

Tax calendarSource

See also: Estimated tax

U

1 term

Income

Unearned income

Income you don't work for: interest, dividends, capital gains, unemployment compensation, taxable Social Security, pensions and annuities. A dependent with more than $1,350 of it in 2025 must file a return.

Source

See also: Earned income, Dependent

W

3 terms

Filing

Withholding

Income tax your employer takes out of each paycheck and sends to the IRS, based on your Form W-4. It is a prepayment: your actual tax is figured on your return, and the difference becomes a refund or a balance due.

Source

See also: Form W-4, Tax refund

Definitions are simplified for everyday use; the linked official pages give the full rules. Figures are for the current tax year unless another year is shown. See our methodology and editorial policy.