Statutory Restrictions Relating to Prior Military Service of the Secretary of Defense [December 13, 2016] [open pdf - 121KB]
"By law, the Secretary of Defense, who has authority, direction, and control over the Department of Defense, is a civilian appointed by the President with the advice and consent of the Senate. Section 113 of Title 10 of the U.S. Code provides that '[a] person may not be appointed as Secretary of Defense within seven years after relief from active duty as a commissioned officer of a regular component of an armed force.' Since such statutory qualification provisions are created by law, they may also be changed, or alternatively, temporarily suspended for the benefit of a specific individual. Since the establishment of the position of Secretary of Defense by the National Security Act of 1947, Congress has acted in one instance to suspend this provision. Enacted on September 18, 1950, at the request of President Truman during the Korean War, P.L. 81-788 authorized the suspension of certain statutory requirements otherwise prohibiting General of the Army George C. Marshall from serving as Secretary of Defense."
CRS Insight, IN10613
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html