The Assistant Secretary of Defense for Health Affairs (ASD(HA)) is chartered under United States Department of Defense Directive (DoDD) 5136.1 in 1994. This DoDD states that the ASD(HA) is the principal advisor to the U.S. Secretary of Defense on all "DoD health policies, programs and activities." In addition to exercising oversight of all DoD health resources, ASD(HA) serves as director of the Tricare Management Activity.