The United States Coast Guard Auxiliary (USCG Aux) is the uniformed auxiliary service of the United States Coast Guard (USCG). Congress established the USCG Aux on June 23, 1939, as the United States Coast Guard Reserve. On February 19, 1941, it was re-designated the United States Coast Guard Auxiliary. The Auxiliary exists to support all USCG missions except roles that require «direct» law enforcement or military engagement. As of 2018, there were approximately 24,000 members of the U.S. Coast Guard Auxiliary.
Collectively the Auxiliary contributes over 4.5 million hours of service each year and completed nearly 500,000 missions in service to support the Coast Guard. Every year Auxiliarists help to save approximately 500 lives, assist 15,000 distressed boaters, conduct over 150,000 safety examinations of recreational vessels, and provide boater safety instruction to over 500,000 students.