Lieutenant Colonel Ko was commissioned in August 1999 after graduating Officer Candidates School. After completing The Basic School and Communications Information Systems Officers Course, he reported to 7th Marine Regiment, Marine Corps Air Ground Combat Center, Twentynine Palms, California where he served as the Assistant Regimental Communications Officer and Communications Platoon Commander.
In January 2001, he was assigned to 2d Battalion, 7th Marines as the Battalion Communications Officer and Communications Platoon Commander. In August 2002, he deployed with 2/7 to Okinawa, Japan in support of the Unit Deployment Program.
In June 2003, he received orders to Inspector-Instructor Staff, 6th Communication Battalion, Brooklyn, New York where he served as the Battalion Personnel Officer.
In June 2004, he was transferred to Inspector-Instructor Staff, Alpha Company, 6th Communication Battalion, Amityville, New York to serve as the Inspector-Instructor. During this tour, he was temporarily assigned to Headquarters Battalion, 1st Marine Division, Camp Pendleton, California and deployed to Camp Blue Diamond, Iraq as the Division Information Management Officer in support of Operation Iraqi Freedom II from August 2004 to March 2005. Upon his return, he resumed his duties as the Inspector-Instructor of Alpha Company, 6th Communication Battalion until he left active duty in April 2008. In July 2009, he joined Alpha Company, 6th Communication Battalion where he served as the Company Executive Officer and Company Commander.
From March 2012 to April 2013, he was mobilized and deployed to Bahrain for duty with U.S. Marine Forces Central Command (Forward) where he served as the Deputy Assistant Chief of Staff G-6, G-6 Plans Officer and G-6 Operations Officer.
In July 2013, he was transferred to 6th Communication Battalion to serve as the Battalion Executive Officer. Following this assignment, he received orders to Force Headquarters Group, Marine Forces Reserve, New Orleans, Louisiana and served as the Assistant Chief of Staff G-6 from August 2016 to August 2018.
Lieutenant Colonel Ko is a graduate of the Marine Corps Command and Staff College (Distance Education) and holds a Bachelor of Arts degree in Economics and Chinese Studies from Swarthmore College. His personal decorations include the Meritorious Service Medal with gold star in lieu of second award, Navy Commendation Medal and Navy Achievement Medal.