In most cases, an applicant for citizenship must have been a lawful permanent resident who has continuously resided in the United States for five years immediately preceding his or her application. Where lawful permanent residence was obtained through marriage to a U.S. citizen, only three years of continuous residence immediately preceding the application is required. An absence of six months or more breaks the continuous residence requirement unless the applicant has a reasonable explanation for the absence.

In addition to the continuous residence requirement, the applicant must have been physically present in the United States for at least half of the five to three years he or she was a legal permanent resident. Furthermore, the applicant must have been a resident for at least three months in the state in which the petition is filed and must be able to speak, read, and write in English.

At the citizenship interview, the applicant will be required to take a short test on the history and political system of the United States. The test may be waived for medical reasons. All citizenship applicants must present proof of having filed tax returns.