Sergeant Major Barnett is a Frederick, MD native. He enlisted in the Marine Corps on 29 August 1990. He attended recruit training at Company K, 3d Recruit Training Battalion, Parris Island, SC in November 1991. After graduating Recruit Training, he completed Marine Combat Training at Camp Geiger, NC. He then attended and graduated from the Ground Radio Maintenance School with the assigned Military Occupational Specialty of 2841, Ground Radio Repairman. He then reported to Bravo Company, 4th Light Armored Reconnaissance Battalion in Frederick, Maryland. While serving with Company B, he held billets as a Ground Radio Repairman, Communications Chief, and Platoon Sergeant.
In February 2003, Sergeant Major Barnett reported to Career Management Team, Headquarters, Marine Corps as a Career Counselor.
Sergeant Major Barnett transferred to Personnel Retrieval and Processing (PRP) Company (-), 4th Marine Logistics Group in Washington, D.C. in September 2006.
In April 2007, Sergeant Major Barnett transferred to the Marine Corps Liaison office at the National Naval Medical Center in Bethesda, MD. While there, he served as the Staff Non-Commissioned Officer in Charge for the Individual Mobilization Augmentee Detachment.
In March 2008, Sergeant Major Barnett returned to PRP Company (-) where he served as a Platoon Commander.
Sergeant Major Barnett mobilized in December 2009 with PRP Detachment in support of Operation Enduring Freedom 10.1. In January 2010, the detachment was attached to Headquarters and Service Company, 1st Marine Logistics Group (Forward). Sergeant Major Barnett held the position of Mortuary Affairs Collection Point Staff Non-Commissioned Officer in Charge at Camp Bastion in Helmand Province, Afghanistan.
Sergeant Major Barnett received orders March 2011 to attach to 3d Marine Division in support of Operation Tomodachi as the Mortuary Affairs Specialist.
In December 2011, Sergeant Major Barnett assumed the responsibilities of Company First Sergeant of PRP Company (-).
Effective August 2012, Sergeant Major Barnett was assigned as the Company First Sergeant of Bravo Company, 4th Combat Engineer Battalion, 4th Marine Division.
In October 2014, Sergeant Major Barnett received orders to report to Enlisted Professional Military Education (EPME), Marine Corps University at Marine Corps Base Quantico. While on active duty, Sergeant Major Barnett served as the Reserve Enlisted Liaison at EPME.
In September 2016, Sergeant Major Barnett assumed the responsibility as the Battalion Sergeant Major of 3d Battalion, 25th Marine Regiment, 4th Marine Division.
Sergeant Major Barnett assumed the responsibility as the Regimental Sergeant Major for 25th Marine Regiment, 4th Marine Division as of April 2018.
Sergeant Major Barnett was selected to serve a three year term with the Marine Corps Reserve Policy Board effective January 2017.
Sergeant Major Barnett currently resides in Frederick, Maryland.
Sergeant Major Barnett’s personal awards include the Meritorious Service Medal with gold star in lieu of second award, the Navy and Marine Corps Commendation Medal with gold star in lieu of second award, Navy and Marine Corps Achievement Medal, and the Military Outstanding Service Medal.