[2] After attending East Lansing High School, Schoomaker graduated from the University of Wyoming in 1969 with a Bachelor of Science degree in education administration.

He holds a Master of Arts degree in management from Central Michigan University,[3] and an Honorary Doctorate of Laws from Hampden–Sydney College.

After being commissioned as a second lieutenant after participating in the Reserve Officers' Training Corps program at the University of Wyoming, Schoomaker went to the United States Army Armor School at Fort Knox.

According to the 9/11 Commission, Schoomaker wanted to take action against Al Qaeda in Afghanistan using his special operators but was unable to gain approval for the mission.

In 2003 Schoomaker returned to active duty to serve as Chief of Staff of the United States Army, at the request of Secretary of Defense Donald Rumsfeld.

Schoomaker is also currently a Director of Aeroflex Incorporated and several private and non-profit companies, including the Special Operations Warrior Foundation.