Sergeant Major Hancock enlisted in the Marine Corps November of 1999. He attended recruit training at Marine Corps Recruit Depot, San Diego, California and graduated March of 2000. He is a graduate of Infantry Training Battalion as a Rifleman, Infantry Squad Leaders Course, Infantry Unit Leaders Training Course, Martial Arts Instructor Trainer (MAIT) course, the United Kingdom Royal Marines Physical Training Instructor 1's Course, First Sergeant's Course, Joint Special Operations Forces Special Operations Academy, and the Navy Senior Enlisted Academy (Distinguished Honor Graduate).
His service in the Operating Forces includes: Team Leader and Machine Gun Section Leader with 1st Battalion, 5th Marines (April 2000- 2003); Squad Leader with 2nd Battalion, 3rd Marines (April 2007-January 2009); Squad Leader and Platoon Sergeant with 3rd Battalion, 3rd Marines (March 2009-April 2011); Platoon Sergeant with 2nd Battalion 4th Marines (November 2014- June 2015); Company 1stSgt with 3rd Battalion 6th Marines (December 2020-May 2022); His most recent tour was serving as Company 1stSgt with 2nd Marine Raider Battalion, Marine Raider Regiment, MARFORSOC (May 2022- August 2025).
His service outside the Operating Forces includes duty as a Combat Instructor at Infantry Training Battalion and Advanced Infantry Training Battalion, School of Infantry (West), Camp Pendleton, California from May 2011 to November 2014.
From August of 2015 until July 2017 he served at the Martial Arts Center of Excellence (MACE) as a MAIT Course Instructor and Plank-owner of the Force Fitness Instructor Course.
From July of 2017 until December of 2020 he was selected for duty with the Royal Marines on the Personnel Exchange Program aboard Commando Training Centre in Lympstone, U.K. as the Lead Advisor to the Royal Marines Close Combat Program.
His personal awards include the Meritorious Service Medal, Navy and Marine Corps Commendation Medal, the Navy and Marine Corps Achievement Medal with 2 gold stars in lieu of third award, and the Combat Action Ribbon with gold star in lieu of second award, and several expeditionary and campaign medals.