Sergeant Major Cain enlisted in the Marine Corps in July 2003 and attended Marine Corps recruit training at MCRD San Diego. Following recruit training Sergeant Major Cain attended infantry training at the School of Infantry west where he earned the Military Occupational Specialty (MOS) of 0311 Rifleman.
Upon completion, Sergeant Major Cain reported to Basic Security Guard School at Chesapeake, Virginia and received the MOS of Marine Corps Security Force Marine, 8152. Upon graduation in March 2004, Sergeant Major Cain reported to Marine Corps Security Force Battalion Kings Bay, Georgia. During which Sergeant Major Cain completed Close Quarter Combat School (CQB) and earned the MOS of 8154. While serving in CQB team 3 he was promoted to Corporal in December 2005. In March 2006, Sergeant Major Cain was transferred to 1st Battalion 5th Marines, 1st Marine Division.
From June 2006 to January 2007, Sergeant Major Cain deployed with the 31st Marine Expeditionary Unit. Following the deployment Sergeant Major Cain attended Infantry Squad Leaders Course at School of Infantry West. In June 2007 he promoted to Sergeant and deployed from November 2007 to June 2008 with the 11th Marine Expeditionary Unit. From May to December 2009, Sergeant Major Cain deployed to Nawa District, Helmand Province, Afghanistan in support of Operation Enduring Freedom. From March to October 2011, Sergeant Major Cain deployed to Sangin District, Helmand Province, Afghanistan in support of Operation Enduring Freedom. Upon return, Sergeant Major Cain was assigned to Marine Combat Instructor School 3-12.
Upon completion of Marine Combat Instructor School, Sergeant Major Cain earned the MOS 0913 and was assigned to F Company, Marine Combat Training Battalion, SOI(W) to serve as a Combat Instructor. While at SOI(W) Sergeant Major Cain was promoted to Staff Sergeant and attended Infantry Unit Leaders Course earning the MOS of 0369. He served as Platoon Commander and primary instructor within MCT Battalion instructor group. In June 2015 Sergeant Major Cain was transferred to 2d Battalion, 8th Marines, 2d Marine Division.
From July 2015 to July 2016 Sergeant Major Cain served as Weapons Platoon Sergeant, and Company Gunnery Sergeant for G Company, 2d Battalion, 8th Marines. In August 2016, Sergeant Major Cain deployed to Black Sea Rotational Force 16.2 Mihail Koglincea Romania, and served as Weapons Platoon Commander. Upon return, Sergeant Major Cain was assigned to II MEF Expeditionary Operations Training Group (EOTG) aboard Camp Lejeune, NC. Sergeant Major Cain was promoted to Gunnery Sergeant in September 2017 and served as Exercise Chief for EOTG, designing the pre-deployment training programs for the 22nd, 24th, and 26th Marine Expeditionary Units, from June 2017 to July 2020.
In July 2020 Sergeant Major Cain executed orders to 3d Battalion, 3d Marine Regiment, 3d Marine Division. Sergeant Major Cain served as Company Gunnery Sergeant for L Company and deployed as part of the Unit Deployment Program Program to Okinawa, Japan. Sergeant Major Cain was frocked to First Sergeant on 1 July 2021 and served as Company First Sergeant for Weapons Company, 3rd Battalion 3rd Marine Regiment. Sergeant Major Cain deployed from June to December 2022 as a part of 3d Bn, 3d Marines Unit Deployment Program.
In June 2023 Sergeant Major Cain reported to Detachment Delta, 4th Law Enforcement Battalion, Force Headquarters Group aboard Joint Base Elmendorf-Richardson, Anchorage, Alaska and served as the Inspector-Instructor First Sergeant.
In June of 2024 he was frocked to Sergeant Major and executed orders to Communication Training Battalion, at Marine Corps Air Ground Combat Center, Twentynine Palms, California. From July 2024 to Aug 2026 Sergeant Major Cain served as the Command Senior Enlisted Leader.
In Aug 2026 Sergeant Major Cain executed orders to 2d Battalion, 7th Marine Regiment, 1st Marine Division and is currently serving as the Command Senior Enlisted Leader.
Sergeant Major Cain's personal awards include: the Purple Heart Medal, the Meritorious Service Medal, the Navy and Marine Corps Commendation Medal with "V" and one silver star in lieu of sixth award, the Navy and Marine Corps Achievement Medal with "V" and three gold stars in lieu of forth award, and the Combat Action Ribbon.