Holcomb has served in multiple combat deployments, including in Mogadishu, Somalia, where he was a part of the surgical team that delivered 48-hour non-stop care to soldiers during the battle that inspired the book and film Black Hawk Down.
From 2002 to 2008, Colonel Holcomb served as the Commander of the U.S. Army Institute of Surgical Research and Trauma Consultant for the Army Surgeon General. He retired from active duty in 2008.