Sergeant Major Efrain Barrientos is a native of New Jersey. He enlisted in the United States Marine Corps on 25 July 2005 and completed recruit training at Marine Corps Recruit Depot Parris Island, SC. Following recruit training, Sergeant Major Barrientos attended Marine Combat Training and Personnel Administration School in Camp Lejeune, NC.
In February 2006, Sergeant Major Barrientos reported to Marine Barracks 8th and I, Washington, DC. In April 2006, he was promoted to the rank of Lance Corporal and in December 2006, he was meritoriously promoted to the rank of Corporal. In October 2007, Sergeant Major Barrientos deployed as an individual augment in support of Operation IRAQI FREEDOM where he served in the billet of Rifleman with Task Force National Capital Region. In October 2008, Sergeant Major Barrientos was promoted to the rank of Sergeant.
In February 2009, Sergeant Major Barrientos reported to 11th Marine Regiment, Camp Pendleton, CA and in June 2009, he was reassigned to 2nd Battalion, 4th Marines and deployed with the 11th Marine Expeditionary Unit as the S-1 Non-Commissioned Officer in Charge and also served as part of the Non-Combative Evacuation Operations Team.
In October 2010, Sergeant Major Barrientos received orders to 1st Battalion, 5th Marines where he deployed to Sangin, Afghanistan in support of Operation ENDURING FREEDOM and was responsible for all casualty tracking and accountability in the area of operations. In April 2011, Sergeant Major Barrientos was meritoriously promoted to the rank of Staff Sergeant.
In April 2012, Sergeant Major Barrientos received orders to VMX-22, Detachment Joint Strike Fighter, Edwards Air Force Base where he served as part of the core cadre to activate the Detachment.
In December 2014, Sergeant Major Barrientos received orders to Marine Security Guard (MSG) School Class 2-15. Upon completion of MSG School, he served as a Detachment Commander at American Embassy Valletta, Malta and American Embassy Conakry, Guinea. In December 2015, Sergeant Major Barrientos was promoted to the rank of Gunnery Sergeant. His detachment was awarded the Region 5 Detachment of the Year Award for 2016 and he was awarded Detachment Commander of the Year for Region 5.
In January 2018, Sergeant Major Barrientos received orders to the Office of the Chairman of the Joint Chiefs of Staff in Washington, D.C. where he served in the Operations Directorate, J-3 as the Operations Chief and Senior Enlisted Marine Element Leader for the Joint Staff.
In May 2019, Sergeant Major Barrientos was promoted to the rank of First Sergeant and received orders to Headquarters Company, Headquarters & Service Battalion, Marine Corps Base Quantico. In May 2020, Sergeant Major Barrientos was reassigned to Manpower and Recruiting Company, Headquarters Battalion, Training and Education Command. In July of 2021, Sergeant Major Barrientos reported to 2d Marine Raider Battalion, Marine Forces Special Operations Command where he served as the Sergeant Major for Marine Special Operations Company F and deployed as the Command Senior Enlisted Leader of Special Operations Task Force 511.2 in support of Operation PACIFIC EAGLE-PHILIPPINES.
In June of 2023, he was promoted to Sergeant Major and assumed the duties and responsibilities as the Command Senior Enlisted Leader of 2d Marine Raider Support Battalion, Marine Forces Special Operations Command. During this time, Sergeant Major Barrientos deployed as the Command Senior Enlisted Leader of Trojan Footprint 24 as the core of a multinational Special Operations Task Force known as Black Sea East.
In January of 2025, Sergeant Major Barrientos reported to 2d Distribution Support Battalion and assumed the duties and responsibilities as the Command Senior Enlisted Leader. During this time, Sergeant Major Barrientos deployed to Norway as part of Marine Rotational Force-Europe in support of Exercise Cold Response 26.
In July of 2026, Sergeant Major Barrientos reported to 7th Marine Regiment to assume the billet of Command Senior Enlisted Leader and is currently serving in this capacity.
Sergeant Major Barrientos holds a Masters Degree in Strategic Leadership from the University of Charleston, Bachelors Degree in Business Administration from American Military University, and an Associates Degree in General Studies from Central Texas College. He is a graduate of Cornerstone, Joint Special Operations Forces Pre-Command Course, Joint Special Operations Forces Senior Enlisted Academy, Marine Corps Senior Enlisted PME, and the U.S. Navy Senior Enlisted Academy.
Sergeant Major Barrientos' personal awards include the Defense Meritorious Service Medal, (4) Meritorious Service Medals, (3) Navy and Marine Corps Commendation Medals, (2) Navy and Marine Corps Achievement Medals, Combat Action Ribbon, (2) Military Outstanding Volunteer Service Medals, and (2) U.S. Department of State Meritorious Honor Awards.