The N-400 may be filed by Lawful Permanent Residents who meet the following requirements:
The immigrant is age 18 or older.
The immigrant is a permanent resident (has a Green Card) now and during all of the past 5 years.
Continuous residence requirement:
An alien must reside in the United States for a continuous period prior to the filing of the naturalization application.I fan alien is not married to an American citizen, he must reside in the U.S. for a continuous period of five years after lawful admission to the U.S. as a permanent resident. If an alien is married to a U.S. citizen, he must reside in the U.S. for a continuous period of three years following lawful admission to the U.S. as a permanent resident. A prolonged absence from the U.S. will break the continuity of the alien's residence in the U.S. for naturalization purposes, although it may not affect the alien's ability to return to the U.S. as a permanent resident. An absence from the U.S. of less than six months does not break the alien's continuity of residence in the U.S. for naturalization purposes.However, an alien's absence from the U.S. of six months or more breaks an alien's continuity of residence. If the break is from six months to one year, the break can be excused if a reasonable explanation can be given for the alien's absence (e.g. overseas employment). If the break is over a year, an alien's continuity of residence can be preserved, and the break can be excused, if steps are taken prior to the expiration of a year abroad to preserve the residence and certain qualifications are met.
Physical Residence Requirement: An alien applying for naturalization must physically reside in the U.S. for one half the period of continuous residence required within the period required for continuous residence. For aliens who are married to a U.S. citizen,the alien must have been physically present in the United States accumulatively for eighteen months within three years prior to the date of filing the application. For aliens not married to aU.S. citizen, the alien must have been physically present in the United States accumulatively for thirty months within five years prior to the date of filing the naturalization application. This requirement is cumulative but not continuous. An alien can leave and come back to the United States within the three or five years as much as he wants as long as he does not break continuity of residence, and as long as his total time spent in the United States adds up to eighteen or thirty months.
The immigrant has resided in his or her current state for at least 3 months. The immigrant's current state is the state where he or she is submitting the application for naturalization The immigrant has not broken any immigration law. The immigrant has not been ordered to
leave the US.
The immigrant has not been a member of the Communist Party at any time during the past 10 years. The immigrant can show at least 5 years of good moral character. The immigrant believes in the principles of the US constitution.
The immigrant can speak, understand, read, and write simple English during an INS interview.
The immigrant can pass the INS test on US history and government.
The immigrant can take an oath of allegiance to the United States.