Linnington is the Chief Executive Officer of Wounded Warrior Project. He previously served as the first permanent Director of the Defense POW/MIA Accounting Agency, following his retirement as a Lieutenant General from the U.S. Army. He served as the Military Deputy to the Under Secretary of Defense (Personnel and Readiness) from 2013 to 2015 and as Commanding General, Military District of Washington and Commander, Joint Force Headquarters-National Capital Region from 2011 to 2013. Linnington also held general officer positions of responsibility as Deputy Commanding General, Fort Benning, Georgia; Commandant of Cadets, United States Military Academy, West Point, New York; and in Kabul, Afghanistan. Linnington graduated from the U.S. Military Academy at West Point.