Defense Information Systems Agency

The Defense Information Systems Agency (DISA), known as the Defense Communications Agency (DCA) until 1991, is a United States Department of Defense (DoD) combat support agency. It is composed of military, federal civilians, and contractors. DISA provides information technology (IT) and communications support to the president, vice president, secretary of defense, the Department of Defense, the combatant commands, and any individual or system contributing to the defense of the United States.