In 1982, President Ronald Reagan named Vessey as Chairman of the Joint Chiefs of Staff. He served until retiring in October 1985, and his tenure was most notable for his high-profile support of the Reagan-era increase in defense spending and military preparedness. Vessey opted to retire before the completion of his second two-year term; according to published reports, he had intended to retire in June 1985 in deference to his wife's wishes to leave Washington, DC for their home in rural Minnesota, but remained on duty until the resolution of the TWA Flight 847 hostage crisis and other ongoing military activities. After leaving the Army, Vessey became involved in efforts to account for military personnel listed as missing in action, and made several trips to Southeast Asia to search for remains as part of resolving the Vietnam War POW/MIA issue. He was awarded the Presidential Medal of Freedom in 1992. Vessey died in North Oaks, Minnesota on August 18, 2016. He was buried at the Minnesota State Veterans Cemetery in Little Falls, Minnesota.