What is the USCIS number located in?

The USCIS number, also known as the Alien Registration Number (A-Number), is typically located on documents issued by U.S. Citizenship and Immigration Services, such as the Green Card, Employment Authorization Document (EAD), or notices related to immigration applications. It usually appears as a series of digits preceded by the letter "A" (e.g., A123-456-789). This number is unique to each individual and is used to track their immigration status and history.