Sergeant Major Garza enlisted in the United States Marine Corps in Houston, TX and completed recruit training with 3d Recruit Training Battalion at MCRD San Diego, CA in October 1993. After completing Marine Combat Training at Camp Pendleton, CA, he completed the Field Radio Operator Course at the Marine Corps Communication-Electronics School in 29 Palms, CA and was assigned to 3d Intelligence Company, 3d Surveillance, Reconnaissance, and Intelligence Group, III MEF in Okinawa, Japan as a field radio operator and surveillance sensor operator. During this tour, he participated in a variety of theater exercises and deployed for counter-drug operations. Transferred back to the U.S. in September 1996 to Camp Lejeune, NC, he was assigned to 2d Intelligence Company, 2d Surveillance, Reconnaissance, and Intelligence Group and 2d Radio Battalion, II MEF. He later served with Fox Company, 2d Battalion, 6th Marine Regiment, 2d Marine Division. During this tour, he again participated in several deployments and counter-drug operations.
In July 1999, he attended Drill Instructor School at MCRD Parris Island, SC and was assigned to 3d Recruit Training Battalion where he served as a Drill Instructor, Senior Drill Instructor, Series Gunnery Sergeant, and Operations Chief for Lima Company, Recruits Awaiting Disposition Section SNCOIC for Headquarters Company, and as a Series Gunnery Sergeant for Kilo Company. In October 2002, he was transferred back to Camp Lejeune, NC and assigned to Charlie Company, 2d Tank Battalion, 2d Marine Division as a Communications Chief and Platoon Sergeant where he deployed in support of Operation Iraqi Freedom I with Regimental Combat Team-5, 1st Marine Division and Operation Iraqi Freedom 2-2 and 04-06 with Regimental Combat Team-1, 1st Marine Division. During Operation Iraqi Freedom 2-2, Charlie Company was heavily involved in combat operations in Fallujah during Operation Al Fajr/Phantom Fury. In June 2005, he reported for duty at the SNCO Academy, Camp Lejeune, NC, serving as a Faculty Advisor and Chief Instructor of the Career Course and SNCOIC of the Sergeants Course.
In June 2008, he reported to Combat Assault Battalion, 3d Marine Division in Okinawa, Japan and served as the Company First Sergeant for Combat Engineer Company and as the acting Battalion Sergeant Major. In July 2009, he deployed in support of Operation Enduring Freedom X with Embedded Training Team 2-8, Regional Corps Advisory Command 3-7 serving as the Team First Sergeant and as a Foreign Security Force Advisor embedded with the 1st Kandak (Infantry), 2d Brigade, 201st Corps of the Afghan National Army in eastern Kunar Province, Afghanistan. Upon return from Afghanistan, he then served as the Company First Sergeant for Truck Company, Headquarters Battalion, 3d Marine Division. Returning to the U.S. in May 2011, he was assigned to 2d Marine Special Operations Battalion, Marine Special Operations Regiment, U. S. Marine Corps Forces Special Operations Command, Camp Lejeune, NC where he served as a Company First Sergeant and then as the Battalion Rear Sergeant Major when the battalion headquarters staff deployed as Special Operations Task Force-West to Afghanistan in support of Operation Enduring Freedom XII. In September 2013, he reported to the School of Infantry-East, Camp Geiger, NC and served as the Sergeant Major, Headquarters and Support Battalion until his posting as the Sergeant Major, Advanced Infantry Training Battalion in December 2014.
From September 2015 to February 2018, he served as the Sergeant Major, Marine Corps Air Station Iwakuni, Japan, Marine Corps Installations Pacific.
Sergeant Major Garza’s personal decorations include the Bronze Star with two Combat V’s and one gold star, Purple Heart, Meritorious Service Medal with three gold stars, Navy and Marine Corps Commendation Medal with one gold star, Navy and Marine Corps Achievement Medal with two gold stars, and the Combat Action Ribbon with one gold star.