Persons who have not acquired U.S. citizenship by birth may be eligible to apply for citizenship in a process known as naturalization. There are several eligibility requirements related to naturalization. The most relevant requirements pertain to how long the applicant has held a green card, and the applicant’s moral character. Eligibility also generally requires a level of proficiency in the English language, knowledge of U.S. history and government, attachment to the principles of the Constitution, and the taking of the Oath of Allegiance.
Eligible applicants for naturalization must also have resided continuously as green card holders in the U.S. for at least 5 years (or 3 years) prior to filing for citizenship, with no single absence of more than one year. In addition, applicants must have been physically present in the United States for at least half of this five (or three) year period. Absences of more than six months will disrupt the applicant’s continuity of residence, unless the applicant can demonstrate that his or her residence was not abandoned during this time.