Quick overview

The IRS uses a combination of filing status, gross income, age, and dependency status to decide whether you must file a federal income tax return for a given tax year. If your gross income equals or exceeds the standard deduction for your filing status (or other special thresholds that apply to dependents, self-employment income, or unearned income), you generally must file. Filing can still be beneficial even when you aren’t required — for example, to claim refundable credits or get a refund of withheld tax.

This article explains how the rules work, common edge cases, professional tips, and where to verify the thresholds for the current tax year (see Sources).

How filing requirements work

  1. Core rule: compare your gross income to the filing threshold
  • The most common test is whether your gross income equals or exceeds the IRS filing threshold for your filing status and age. For most taxpayers, that threshold matches the standard deduction amount for the status.
  • Gross income means all income you receive in the form of money, goods, property, and services that isn’t explicitly tax-exempt (wages, taxable interest, dividends, business income, capital gains, some Social Security, etc.). See IRS Publication 501 for details.
  1. Exceptions and special tests
  • Dependents: If someone else can claim you as a dependent, special rules apply. Dependents must file under different thresholds based on earned income, unearned income (investment income), and total gross income. See our in-depth explainer: Filing Requirements for Dependents: When Kids Need to File.
  • Self-employment: If you have net earnings of $400 or more from self-employment, you must file a return to pay self-employment tax, even if your gross income is below the usual threshold.
  • Taxes owed or refundable credits: You must file if you owe certain taxes (for example, household employment taxes) or to claim refundable credits such as the Earned Income Tax Credit (EITC), Additional Child Tax Credit, or refundable portions of other credits.
  1. Filing status specifics
  • Single: Used by unmarried taxpayers or those legally separated under a divorce or separate maintenance decree.
  • Married filing jointly (MFJ): Typically offers the highest threshold and combined tax rates; couples usually file MFJ unless there’s a specific reason not to.
  • Married filing separately (MFS): Each spouse uses separate thresholds — often low — and certain credits aren’t available.
  • Head of household (HOH): For unmarried taxpayers who provide a home for a qualifying person; HOH has higher thresholds and more favorable rates than single.
  • Qualifying widow(er) with dependent child: Applies for up to two years after the year a spouse dies if the surviving spouse meets criteria.

For more on qualifying for HOH and its benefits, see: Head of Household: Who Qualifies and Why It Matters.

Common examples (illustrative — check current-year thresholds)

  • Example 1 — Single, under 65: If you are single, under 65, and your gross income exceeds the filing threshold for single filers that year, you must file. For reference, tax year 2023 thresholds required single filers under 65 to file if gross income was $13,850 or more; those amounts change with inflation.

  • Example 2 — Married filing jointly: Married couples who file jointly generally have a higher combined threshold (roughly double single). Even when one spouse has little or no income, the MFJ test uses combined gross income and age rules.

  • Example 3 — Dependents (teen with a summer job): A student who can be claimed as a dependent must compare earned income and unearned income against special dependent thresholds. Even modest investment income can trigger a filing requirement for dependents.

  • Example 4 — Gig worker: If you earned $600 in gig income and had no other income, you may still need to file because self-employment net earnings (after expenses) of $400+ require filing and paying self-employment tax.

Who is affected / eligible

  • Most wage earners: If your wages plus other gross income meet or exceed the threshold tied to your filing status and age, you must file.
  • Self-employed individuals: Net earnings of $400 or more require filing.
  • Dependents: Young adults and others claimed as dependents must run a different set of tests. See our dependent filing guide linked above.
  • Nonresident aliens and part-year residents: Residency status changes the filing test; see our dedicated guide for nonresidents and part-year residents.

Real-world scenarios from practice

  • Married couple deciding MFJ vs. MFS: In my practice, small decisions about filing status often change whether a return is required at all — for instance, a couple with one spouse on disability and the other with modest wages could be required to file only if they file separately, but not if they file jointly. Filing jointly also unlocks credits (EITC in eligible cases) that can produce refunds.

  • Low-income worker who still files: A client earning under the filing threshold still filed to recover withheld payroll tax and qualify for refundable credits; she received a refund larger than the amount she paid in.

  • Teen with investments: A dependent teenager with taxable interest and dividends exceeded the unearned income limit and therefore had to file and pay taxes on those earnings.

Professional tips and practical checklist

  • Don’t assume “no filing required” means “don’t file.” If you’ve had federal tax withheld or are eligible for refundable credits (EITC, Additional Child Tax Credit), file to claim the money.
  • Run a simple checklist each year before filing: filing status, age(s) at year-end, gross income types (earned vs. unearned), and whether someone else can claim you as a dependent.
  • Self-employment: Track deductible business expenses so you can determine net earnings subject to self-employment tax and filing rules.
  • Consider timing: When you marry, divorce, or become a single head of household during the year, evaluate which status produces the best outcome and whether it changes your filing obligation. See our article on switching status: When to Switch Filing Status Mid-Year.

Common mistakes and misconceptions

  • Mistake: Assuming threshold equals take-home pay. Gross income includes pre-tax contributions and many other items; net or take-home pay is not the measure for filing tests.
  • Mistake: Ignoring dependency rules. A dependent can still owe taxes or be required to file under the dependent tests.
  • Mistake: Overlooking self-employment tax. Those with small gig-economy income sometimes miss that net earnings of $400+ force a filing even if overall income looks low.

Penalties and consequences for not filing

  • Failure-to-file penalty: If you are required to file and don’t, the IRS can assess penalties and interest on unpaid tax. The failure-to-file penalty is generally larger than the failure-to-pay penalty, so file even if you cannot pay the full amount; setting up a payment plan is better than not filing.
  • Lost refunds: You have a limited time to claim certain refunds and credits — if you don’t file within the statute of limitations (usually three years), you may forfeit a refund.

Frequently asked questions

  • If my income is below the threshold, should I still file? Often yes — to claim refunds and refundable credits. If you had federal withholding you almost always want to file.
  • What if I’m claimed as a dependent? You must follow the dependent filing tests. Even modest earned income or investment income can create a requirement.
  • Does Social Security count? Generally up to a portion of Social Security benefits may be taxable and count toward gross income; if Social Security is your only income and it’s not taxable, you may not be required to file.

How to check the current-year thresholds

Always verify thresholds for the tax year you are filing. The authoritative source is IRS Publication 501, “Dependents, Standard Deduction, and Filing Information” (IRS). The IRS also publishes annual inflation adjustments and news releases that list the current-year standard deduction and filing thresholds. For personalized situations (multi-state issues, residency, or significant life changes), consult a tax professional.

Authoritative sources and recommended reading:

Professional disclaimer

This article is educational and based on general rules from IRS guidance and professional experience. It does not replace personalized tax advice. For decisions tied to your situation — especially with multiple income sources, nonresident status, or complex dependency questions — consult a qualified tax professional or CPA and review IRS Publication 501 for the tax year you are filing.

Last reviewed: 2025 — verify the current tax year thresholds on IRS.gov before filing.