First Sergeant Yuen entered the Marine Corps in October 2004 and graduated from recruit training, MCRD Parris Island, South Carolina in January 2005. After completing Infantry Training Battalion at Camp Geiger, NC and Marine Corps Security Forces Basic Security Guard Course at Chesapeake, VA, First Sergeant Yuen received orders to Naval Air Station Patuxent River, MD. While stationed in NAS Patuxent River, MD, First Sergeant Yuen was promoted to Lance Corporal in December 2005 and served as a Corporal of the Guard.
In October 2006, First Sergeant Yuen reported to 3rd Battalion, 1st Marines, 1st Marine Division, Camp Pendleton, CA. In April 2007, BLT 3/1 was attached to the 13th MEU and participated in Operation Iraqi Freedom in Al Anbar Province. Upon return, First Sergeant Yuen was promoted to Corporal in December 2007. In July 2008, he was meritoriously promoted to Sergeant and then deployed with BLT 3/1 on the 31st MEU to Okinawa, Japan, the Philippines, and South Korea. In April 2010, First Sergeant Yuen deployed once more with BLT 3/1 to Helmand Province, Afghanistan in support of Operation Enduring Freedom. During his tour, he served as Rifleman, Team Leader, Squad Leader, and Platoon Sergeant.
Following his return from his tour with BLT 3/1, First Sergeant Yuen was re-assigned to Drill Instructor School, MCRD San Diego, CA.
Upon completion of the course, he was assigned to 2nd Battalion, Hotel Company where he successfully completed 7 cycles: 3 cycles as a Drill Instructor and 4 cycles as a Senior Drill Instructor. In June of 2014, First Sergeant Yuen received orders to 2nd Battalion, 4th Marines in Camp Pendleton, CA.
Once at 2nd Battalion, 4th Marines, First Sergeant Yuen was selected to be the 2nd Platoon Sergeant in Fox Company. In October of 2014, he was promoted to the rank of Staff Sergeant. In November of 2014, First Sergeant Yuen deployed with Fox Company on the 31st MEU out of Okinawa, Japan. In May of 2015, he was assigned to be the Weapons Platoon Sergeant/Chief Coxswain and deployed with them on the 31st MEU in April of 2016. In October of 2016, First Sergeant Yuen returned from deployment and was assigned to the billet of Fox Company Gunnery Sergeant.
In August of 2017, First Sergeant Yuen reported to Marine Corps Security Force Battalion Bangor, WA. Upon arrival to MCSFBn Bangor First Sergeant Yuen was assigned as the Headquarters and Service Company Gunnery Sergeant. In September of 2018, he was promoted to Gunnery Sergeant and reassigned to serve as the Bravo Company Gunnery Sergeant.
In August of 2020, First Sergeant Yuen reported to Marine Forces Korea and was assigned as the Current Operations Chief. In September of 2022 First Sergeant Yuen was selected to serve as the Executive Officer for the United States Forces Korea Command Sergeant Major. In June of 2023 First Sergeant Yuen was promoted to his current rank and received orders to 4th CEB D Co. in Knoxville, TN were he currently serves.
First Sergeant Yuen's personal awards include the Defense Meritorious Service Medal, the Navy and Marine Corps Commendation Medal with combat distinguishing device with 1 gold star in lieu of 2nd award, Navy and Marine Corps Achievement Medal with 2 gold stars in lieu of 3rd award, and the Combat Action Ribbon.