Sergeant Major Cossey assumed the billet of Battalion Sergeant Major at 1st BN 23d Marine Regiment in May of 2017.
He attended recruit training at MCRD San Diego on 15 December 1993. After recruit training and MCT he was ordered to the Marine Corps Communications Electronics School (MCCES) for the Field Radio Operators Course where he graduated third overall at the rank of Private First Class.
He checked into Fox Battery, 2d Battalion, 14th Marine Regiment in Oklahoma City, OK in June of 1994. While at F Btry he performed the duties of Radio Operator (RO) to include the RO for the Forward Observer (FO) section, Battery NCO, Vehicle Maintenance NCO, Quality Control NCO, and Embarkation NCO. He was promoted to the rank of Lance Corporal in March 1995 and to the rank of Corporal in 1997, and Sergeant in 2000.
In October 2001 Sgt Cossey joined Headquarters Battery, 14th Marine Regiment, at Naval Air Station Joint Reserve Base (NAS/JRB) in Fort Worth, TX. He held the billets of squad leader and the embarkation chief. In 2001 he attended the Sergeants Residents Course in Neosho, MO.
In November 2003, he joined Rocket Battery F who was beginning their transition from Cannons to Rocket Artillery. In August 2005 he was promoted to the rank of Staff Sergeant. Duties performed include HQ Platoon Sergeant and Radio Chief. He was mobilized with Battery F in March of 2007, and deployed in support of Operation Iraqi Freedom 06-08. He filled the detachment Radio Chief, Headquarters and Service Platoon Sergeant, and a Watch Officer billets (concurrently). In October 2008 he was promoted to the rank of Gunnery Sergeant. Duties performed include Radio Chief, Headquarters Platoon Sergeant, and Battery First Sergeant (respectively). In July 2009 GySgt Cossey attended the Resident Advanced Course in Quantico, VA.
In May 2011 he transferred from Rocket Battery F to the Reserve Support Personnel (RSP) to fill the Individual Mobilization Augmentee (IMA) billet of Administration Chief.
In April 2012 he was selected to the rank of First Sergeant and assigned to the Anti-Tank Training Company, 4th Marine Division in Broken Arrow, OK. He attended the First Sergeants course in Quantico, VA in July 2012. The Company was supposed to be re-assigned as a Tow/Scout Platoon as of July 2013.
In July 2013 he was reassigned as Battery First Sergeant at Rocket Battery F, 2d BN, 14th Marine Regiment in Oklahoma City, OK He attended the 1stSgt/MSgt Regional Seminar at Camp Pendleton, CA in July 2014.
In July 2015 First Sergeant Cossey was assigned to Headquarters Battery, 14th Marine Regiment at NAS/JRB, Fort Worth, TX. He attended the Senior Leaders Workshop on board MARFORRES Headquarters, New Orleans, LA and the Cornerstone Course at MCB Quantico, VA.
In April 2017 Sergeant Major Cossey was promoted to his current rank and received orders to 1st Battalion, 23d Marines located in Houston, TX. He assumed the duties as the Battalion Sergeant Major in May 2017.
He has earned a Bachelor of Science in Management Information Systems and Master of Science in Construction Administration.
Personal Awards include: Navy and Marine Corps Commendation Medal, Navy and Marine Corps Achievement Medal, and Saint Barbara Medal.