The U.S. Public Health Service Commissioned Corps is a uniformed service of public health professionals who serve in various agencies and departments of the federal government, including the Department of Health and Human Services, the Department of Defense, and the Department of Homeland Security. The Commissioned Corps was established in 1798 and is headquartered in Rockville, Maryland. Members of the Commissioned Corps are trained to respond to public health emergencies and provide healthcare services to underserved populations.