When you have had your green card for three years (and been married to a U.S. citizen for those years) or five years (for almost everyone else) then you may be eligible to apply for naturalization to become a U.S. citizen.
Your eligibility also depends on how much time you have spent physically present in the U.S. In general, you have to have been here for at least half of the qualifying time period. You also must not have been outside of the country for more than six months, or else you could have a break in your residency.
ℹ️ Recent changes: if you apply now, you will take the 2025 version of the civics test. The officer asks up to 20 questions from a list of 128, and you need 12 correct answers to pass. USCIS has also been reviewing applicants' full histories more aggressively, including things like traffic records and tax issues, under a stricter "good moral character" review. A clean, well-prepared application matters more than it used to.
Since August 2026, USCIS does not have to ask you for missing evidence before denying an application. What that means for your filing.
ℹ️ One bar catches people by surprise: helping another person enter the country unlawfully counts against good moral character, and it reaches helping a family member across, not only paid smuggling. It applies to the period USCIS reviews rather than your whole life, and unlike some other issues there is no allowance for sympathetic circumstances. If anything in your history could look like this, raise it with an attorney before you file rather than after.