Lujan grew up in Littleton, Colorado before joining the United States Marine Corps in 1993 and was honorable discharged in 1997, where he returned to Colorado to become more active in parenting his young daughter Emily. After the attacks of September 11, 2001, he re-enlisted in the Marine Corps and was subsequently deployed to Kuwait in support of Operation Iraqi Freedom. During the initial ground war Lujan was injured while riding in the rear of a vehicle and suffered two ruptured discs in his lower back. Complications from the surgery resulted in paralysis of his lower legs. He was medically retired from the Marine Corps in 2006 due to those injuries.