USCIS Number

A USCIS Number, also known as an Alien Registration Number (A-number) or Alien Number, is a unique 7-, 8-, or 9-digit number assigned to a noncitizen by the Department of Homeland Security (DHS). The USCIS Number is used to identify immigrants who apply for permanent residency in the United States and can be found on the front of the Permanent Resident Card (Green Card).