 Receiving his fourth star in July 2008, Amos assumed duties as the 31st Assistant Commandant of the Marine Corps, based at the Pentagon in Arlington, Virginia.In June 2010, Amos was recommended Secretary of Defense Robert Gates for nomination as the 35th Commandant of the Marine Corps.Amos was nominated by President Barack Obama on July 20, who interviewed him for the job on June 17. and confirmed by the Senate Armed Services Committee on September 21, and confirmed shortly thereafter.