The Defense Distinguished Service Medal is awarded only while assigned to a joint activity. Normally, such responsibilities deserving of the Defense Distinguished Service Medal are held by the most senior officers such as the Chairman and Vice Chairman of the Joint Chiefs of Staff, the Chiefs and Vice Chiefs of the Services, and Commanders and Deputy Commanders of the Combatant Commands, the Director of the Joint Staff etc., whose duties bring them frequently into direct contact with the Secretary of Defense, the Deputy Secretary of Defense, and other senior government officials. In addition, the Defense Distinguished Service Medal may also be awarded to other service members whose direct and individual contributions to national security or national defense are recognized as being so exceptional in scope and value as to be equivalent to contributions normally associated with positions encompassing broader responsibilities.