Lavelle attended the Air War College in 1956–57 and then spent the next five years at Headquarters U.S. Air Force as deputy director of requirements; secretary of the Weapons Board; and deputy director of programs. While in the Pentagon, he was principally responsible for the reorganization of the Air Force Board system and the establishment of program control through the Program Review Committee and the Weapons Board. He was awarded an oak leaf cluster to his Legion of Merit at the end of this tour of duty.