The United States Army Nurse Corps (AN or ANC) was formally established by the U.S. Congress in 1901. It is one of the six medical special branches (or "corps") of officers which – along with medical enlisted soldiers – comprise the Army Medical Department (AMEDD). The ANC is the nursing service for the U.S. Army and provides nursing staff in support of the Department of Defense medical plans. The ANC is composed entirely of registered nurses (RNs).