is the process by which a foreign national becomes a citizen of the United States. It is the last step of the immigration process and is one of the most important decisions an immigrant can make as it creates a unique bond with this great nation.  You can become a naturalized citizen in one of two ways: Naturalization is the process by which U.S. citizenship is granted to a lawful permanent resident after meeting the requirements established by Congress in the Immigration and Nationality Act (INA). Acquisition of citizenship is obtained through U.S. citizenship parents either at birth or after birth, but before the age of 18.