Major Grey enlisted in the Marine Corps and attending recruit training at Marine Corps Recruit Depot (MCRD), San Diego, California from August to November of 1994.
Following recruit training he attended Marine Combat Training at Camp Pendleton, CA, where he was assigned the Military Occupational Specialty (MOS) Landing Support Specialist 0481. He served as a Longshoreman as part of 3rd Force Service Support Group (FSSG), 3rd Landing Support Battalion (LSB) Beach and Terminal Operations Company (BTO Co), Okinawa, Japan. In 1996, he transferred to 1st FSSG, 1st LSB, BTO Co, Camp Pendleton, California. While at 1st LSB, he attended Army Airborne School and was subsequently reassigned to 1st Air Delivery Platoon as a heavy-pack parachute rigger. During his time working at the para-loft he amassed 73 aircraft jumps.
In 1999, he was accepted to the Marine Enlisted Commissioning Education Program (MECEP). He attended the MECEP Preparatory course at MCRD San Diego, and upon graduation he was assigned to the University of Colorado, Boulder, Colorado to begin his undergraduate work. Following his freshman year he attended Marine Corps Officer Candidates School (OCS) in Quantico, Virginia. While at Colorado he was a member of the Honors Society and joined the Varsity football team as a walk-on kicker and punter. In May 2003, he graduated with a Bachelor’s of Arts degree in History and in Secondary Education. He also received his teaching credentials for the state of Colorado.
Upon commissioning he attended The Basic School (TBS) in Quantico, Virginia, where he was assigned the MOS 6602, Aviation Supply Officer. Following TBS, he reported to the Basic Aviation Logistics Course in Athens, Georgia for technical training. His first tour in the operating forces as a commissioned officer was with Marine Aviation Logistics Squadron 12 (MALS-12) located in Iwakuni, Japan. There he served as a Consumables Management and Supply Response Division Officer. He was later assigned as the MALS-12 Squadron Operations, Logistics and Training Officer.
In July 2007, he reported to the University of Nebraska, Lincoln, Naval Reserve Officers Training Corps (NROTC) Unit, where he served as the Marine Officer Instructor until December 2010. During his tenure he earned a Master’s of Arts degree in Education Administration.
In December of 2010, Major Grey reported to the 33rd Fighter Wing, Eglin Air Force Base, Florida, where he served as the Aviation Supply Officer for the 33FW and for the F-35 Supply Department. In addition he served as the Operations Officer for the Maintenance Operations Squadron until its deactivation in the summer of 2013. During this time he laid the brick and mortar for future Aviation Supply Operations in support of all three variants of the F-35 Joint Strike Fighter aircraft; the first 5th Generation Aircraft for the United States Marine Corps. While at Eglin, he earned a Master’s of Science Degree in Operations Management from the University of Arkansas, Fayetteville Arkansas.
In July 2015, Major Grey reported to Marine Aviation Training Support Squadron One to serve as the Commanding Officer. Major Grey’s personal decorations include the Navy Commendation Medal (3rd award) and the Navy Achievement Medal (4th award).