Form N-400 Application for Naturalization

You must be at least 18 years old, a lawful permanent resident for at least 5 years (3 years if married to a U.S. citizen), physically present in the U.S. for at least half that period, and of good moral character. List all trips outside the U.S. during the statutory period. Disclose your full employment and residential history. The process includes biometrics, an interview with English and civics tests, and the oath of allegiance. Filing fee is $760.