Sergeant Major Alarcon enlisted in the United States Marine Corps on 11 September 2000 from Recruiting Station Albuquerque, New Mexico. In December 2000 he graduated Recruit Training from Marine Corps Recruit Depot (MCRD), San Diego. After completing Recruit Training, Private Alarcon attended Marine Combat Training at Camp Pendleton, California. Next, he attended the Enlisted Warehousing Basic Course at Camp Johnson, North Carolina, earning the Military Occupational Specialty (MOS) 3051.
In February 2001, he reported to 3D Light Armored Reconnaissance Battalion (3D LAR Bn), 1st Marine Division, Twenty-nine Palms, California. Private Alarcon served as a Warehouse Clerk. While assigned to 3D LAR Bn, Private First Class Alarcon was meritoriously promoted to Lance Corporal. Lance Corporal Alarcon volunteered to be a Marksmanship Instructor with Marksmanship Training Unit (MTU), and was transferred to Headquarters Battalion, MAGTAFTC. Upon returning, Corporal Alarcon deployed in support of Operation Iraqi Freedom (OIF) as a 50 Caliber Machine Gunner and Operation Enduring Freedom (OEF) in Iraq as a Squad Automatic Weapon Gunner.
Corporal Alarcon reenlisted in 2004 and was transferred to Headquarters and Support Battalion (HQ&S Bn), Marine Corps Base, Camp Pendleton, California, where he served as the Assistant Warehouse Chief and Firing Non-Commissioned Officer for the Funeral Detail. While assigned to HQ&S Co, he was promoted to Sergeant. In January 2007, Sergeant Alarcon volunteered and received orders for Recruiting School at MCRD, San Diego.
Upon graduating, Sergeant Alarcon reported to Recruiting Station Albuquerque as a Recruiter. As a new recruiter, he was selected to be the Assistant Staff Non-Commissioned Officer for Albuquerque South and selected to be a Rifleman for the Color Guard. As a result of his intense work ethic, he was subsequently meritoriously promoted to Staff Sergeant in January 2009.
After a successful tour of duty, Staff Sergeant Alarcon reported to Marine Aircraft Group 13 (MAG-13), 3rd MAW, Marine Corps Air Station (MCAS) Yuma, Arizona. During this tour, Staff Sergeant Alarcon deployed to Afghanistan in support of OEF with Marine Wing Headquarters Squadron 3 (MWHS-3), 3rd MAW, MCAS Miramar. After returning from deployment in August 2012, Staff Sergeant Alarcon served in a variety of billets, including: Camp Commandant for Integrated Training Exercise (ITX), Substance Abuse Control Officer (SACO), Operational Stress Control and Readiness (OSCAR) Trainer, the High Mobility-Multi-purpose Wheeled Vehicle (HMMWV) Assistance Trainer (HEAT) and Mine-Resistant Ambush Protected Egress Trainer (MET).
In September 2014, Staff Sergeant Alarcon transferred to 1st Tank Battalion, 1st Marine Division, Twenty-nine Palms, California. He served in various billets, including: 1st Tank Battalion Warehouse Chief, Vehicle Commander, OSCAR Trainer, and the Marine Ball Coordinator. While assigned to HQ&S Co, he was promoted to Gunnery Sergeant. He served in additional billets such as the Company Gunnery Sergeant for HQ&S Co and the 1st Tank Battalion Career Planner.
In August 2016, Gunnery Sergeant Alarcon transferred to Headquarters Company, Headquarters Regiment, 1st Marine Logistics Group, Camp Pendleton, California. He served as the Headquarters Company Gunnery Sergeant and the Headquarters Company First Sergeant.
In August 2017, Gunnery Sergeant Alarcon received Temporary Additional Duty orders to Combat Logistics Battalion 13, 13th Marine Expeditionary Unit, I Marine Expeditionary Force, Camp Pendleton, California. He served as the Battalion Gunnery Sergeant. While assigned to Combat Logistics Battalion 13, he was frocked to First Sergeant.
In April 2019, First Sergeant Alarcon transferred to 1st Radio Battalion, I Marine Expeditionary Force Information Group, I Marine Expeditionary Force, Camp Pendleton, California. He served as the Bravo and Alpha Company First Sergeant.
In April 2021, First Sergeant Alarcon transferred to 3d Intelligence Battalion, III Marine Expeditionary Force Information Group, III Marine Expeditionary Force, Camp Hansen, Okinawa. He served as the Battlespace Surveillance Company First Sergeant. In June 2023, he was promoted to Sergeant Major.
In June 2023, Sergeant Major Alarcon reported to Recruiting Station Albuquerque, 8th Marine Corps District, Western Recruiting Region. He is currently serving as the Recruiting Station Sergeant Major.
Sergeant Major Alarcon’s personal decorations include: Navy and Marine Corps Commendation Medal with 1 gold star, Navy and Marine Corps Achievement Medal with 1 silver star and 2 gold stars, and the Good Conduct Medal with 1 silver star.