Miller was commissioned into the
United States Air Force on May 29, 1993. After commissioning he served as a
Gold Bar Recruiter in
Rutgers University at
New Brunswick, New Jersey with the Air Force Reserve Officer Training Corps Detachment 48. After that, he went to undergraduate missile training at
Vandenberg Air Force Base,
California. He finished the training as an outstanding performer. He served as commander for two years, after which he was reassigned as director of plans, programs, and financial management with the
Air Force Space Command (AFSPC) at Peterson Air Force Base. While at AFSPC, he was promoted to brigadier general in 2018. He was tapped by General
John W. Raymond to lead a
task force on conducting detailed planning and implementation for the reestablishment of the
United States Space Command. He served in this position for a year, after which he was reassigned as the first assistant
deputy chief of space operations for operations, cyber, and nuclear. Six months later, he moved back to Peterson Air Force Base as director of operations, training, and force development of the
United States Air Force. In September 2023, Miller was nominated for promotion to lieutenant general and assignment as
commander of Space Operations Command (SpOC). He would replace Lieutenant General
Stephen Whiting who was selected to serve as
commander of the United States Space Command. His nomination was among the hundreds of military nominations stalled by Senator
Tommy Tuberville's hold over the Pentagon's abortion policy. While he waited for confirmation, he was temporarily assigned as special assistant to the
vice chief of space operations while stationed at Peterson. His nomination was confirmed on December 5, 2023. On January 9, 2024, he was promoted to lieutenant general and took command of SpOC. As SpOC commander, he is responsible for the generation, presentation, and sustainment of Space Force operational forces. ==Awards and decorations==