Becoming a U.S. citizen: N-400 basics

Who can apply, when to file, what it costs, and the red flags to check first.

Updated November 4, 2026 · Reviewed by Ettrick M. Campbell, Esq.

Citizenship means voting, a U.S. passport, no more green card renewals, and the ability to petition for more relatives. The application is Form N-400.

Are you likely eligible to apply?

The basic requirements:

  • You've had your green card for 5 years, or 3 years if you've been married to and living with a U.S. citizen that whole time (and they've been a citizen for those 3 years).
  • Continuous residence: no single trip abroad that broke your residence (trips of 6 months or more raise questions; 1 year or more usually breaks it).
  • Physical presence: you've been inside the U.S. for at least half of that 5-year (or 3-year) period.
  • You've lived in your state or USCIS district for at least 3 months.
  • Good moral character, and you can pass the English and civics tests (some older applicants qualify for exceptions).

You can file up to 90 days early, before your 5-year (or 3-year) anniversary.

What it costs

  • $760 by mail, $710 online.
  • $380 reduced fee for lower household incomes (paper filing).
  • Always confirm at uscis.gov/g-1055.

What you'll need to gather

  • Your green card (front and back).
  • Every trip outside the U.S. in the last 5 years, with dates.
  • Your home addresses and employers or schools for the last 5 years.
  • Marriage and divorce history, and information about your children.
  • Tax filing history.
  • Any arrest, citation, or court records, even if dismissed or sealed.

Red flags: talk to a lawyer before filing

Applying for citizenship means USCIS reviews your whole history again. Get advice first if you:

  • Were ever arrested, charged or convicted of anything, anywhere.
  • Ever claimed to be a U.S. citizen or voted in a U.S. election.
  • Took long trips abroad, or lived outside the U.S. for long periods.
  • Didn't file taxes, or owe child support.
  • Are a man who lived in the U.S. between ages 18 and 26 and didn't register for Selective Service.
  • Got your green card through a marriage or petition that USCIS might question.

The process

  1. File the N-400 (online or by mail).
  2. Biometrics appointment (fingerprints).
  3. Interview, with the English and civics tests.
  4. Decision, then the oath ceremony, where you become a citizen.

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