Requirements for becoming a U.S. citizen include holding a green card and residing in the United States for at least 5 years before applying, proficient English language skills, an understanding of American history and government and being of good moral character, according to U.S. Citizenship and Immigration Services. People can also obtain citizenship through birth.
Citizenship is granted at birth to people born in the U.S. and in relevant territories. It is also automatically granted to people whose parents are American citizens at their birth, reports the Department of Homeland Security. However, other people must become citizens through the naturalization process.
To start the naturalization process, prospective citizens must first obtain a green card. A green card offers permanent residence in the United States, which is an essential part of gaining citizenship.
Before applying for citizenship, green card holders must have permanent resident status for at least 5 years. During this time, they must maintain a continuous residence in the U.S. Although they may leave the country during this time, they must be "physically present" in the country for a minimum of 30 months of the 5 years prior to application.
Applicants who fulfill these requirements, are at least 18 years of age, and can demonstrate a good knowledge of English and U.S. civics can fill out Form N-400 to apply for citizenship through naturalization.