If you meet certain requirements, you may become a US citizen either at birth or after birth. Use this form to apply for US citizenship.Learn about the steps for permanent residents applying for citizenship through marriage to become naturalized in just three years. Immigrant visa for a Spouse of a U.S. Citizen (IR1 or CR1) - An immigrant Petition for Alien Relative, Form I-130 is required. You'll need to file form N-400 to become a naturalized U.S. citizen. You must be married to a citizen the entire time; and your spouse must have been a U.S. citizen for the entire time. Usually, someone who is not a citizen needs to live in the U.S. as a lawful permanent resident for at least 5 years to apply for citizenship. A couple who intends to be married in New York State must apply in person for a marriage license to any town or city clerk in the state. To become a permanent resident, you need to prove you are still married after 2 years. Your relative is required to file an immigrant visa petition, Form I-130, on your behalf with the U.S. Citizenship and Immigration Services (USCIS).