Sergeant Major Johnson enlisted in the Marine Corps on 5 November 1996 and attended recruit training at Company L, 3rd Recruit Training Battalion, Marine Corps Recruit Depot Parris Island, SC. Upon graduation, he reported to Marine Combat Training (MCT) at Camp Geiger, NC. Upon completion of MCT, he reported to Marine Corps Communication-Electronics School (MCCES)in 29 Palms, CA where he was designated the MOS of 2531, Field Radio Operator.

Following the Field Radio Operator's Course, Sergeant Major Johnson reported to 5th Force Reconnaissance Company, Okinawa, Japan. In August 1997, he was promoted to the rank of Lance Corporal. While at 5th Force Reconnaissance Company Sergeant Major Johnson conducted various unit deployments throughout South East Asia.

In May 1998, he was promoted to the rank of Corporal. In August 1998, 5th Force Reconnaissance Company was deactivated and he
was reassigned to 3d Reconnaissance Battalion. In April 1999, Sergeant Major Johnson was promoted to the rank of Sergeant. In June 1999, he was assigned to Bravo Company, 1st Platoon as the Platoon Communications Chief. While with Bravo Company he deployed with the 31st Marine Expeditionary Unit (MEU) and supported humanitarian operations in East Timor. In November 2000, he was honorably discharged from the Marine Corps.

On 11 September 2001, Sergeant Major Johnson reentered the Marine Corps and reported to 1st Force Reconnaissance Company, Camp Pendleton, CA. While assigned there he served as Equipment NCO for the communications platoon. In January 2003, Sergeant Major Johnson deployed in support of Operation Iraqi Freedom. While deployed he served as Radio Supervisor and Equipment NCO. In February 2004, he returned to Iraqi and served as the Platoon Communications Chief for 8th Platoon. In January 2005, Sergeant Major Johnson was promoted to the rank of Staff Sergeant. In February 2005, Sergeant Major Johnson reported to Inspector-Instructor Staff, Battery N, 5th Battalion, 14th Marines where he served as the Communications Chief. In September 2005, Sergeant Major Johnson deployed with Battery N to Camp Fallujah, Iraq in support of Operation Iraqi Freedom. In March 2008, Sergeant Major Johnson attended Marine Security Guard School Class 3-08 and earned the MOS of 8156. Upon graduating he was assigned to American Embassy Lomé, Togo where he served as Detachment Commander. In December 2008, he was promoted to the rank of Gunnery Sergeant. In August 2009, Sergeant Major Johnson was assigned to American Embassy Montevideo, Uruguay serving as Detachment Commander.

In May 2011, Sergeant Major Johnson reported to Marine Air Support Squadron 1 (MASS-1) in Cherry Point, NC. There he served as Company First Sergeant for Communication and Electronics Company. In April 2013, Sergeant Major Johnson was assigned as an individual augment to II Marine Expeditionary Force Forward (II MEF Fwd) in support of Operation Enduring Freedom, Camp Leatherneck, Afghanistan. Upon completion of the deployment he returned to MASS-1 as the Company First Sergeant for Air Support Company. In September 2014, Sergeant Major Johnson was transferred to MCCES and was assigned to Company B, Transmission Training Section where he served as the Chief Instructor for the Mobile Wideband Multichannel Equipment Operator's Course. In January 2015, Sergeant Major Johnson was promoted to First Sergeant and transferred to 3rd Battalion, 7th Marines where he assumed the duties as the Company First Sergeant for Company L.

In February 2015, Sergeant Major Johnson was reassigned to 3d Light Armored Reconnaissance Battalion and assumed duties as Company First Sergeant for Company B. In May 2016, Sergeant Major Johnson deployed with Company B as a part of the Unit Deployment Program. In June 2017, Sergeant Major Johnson reported to Headquarters and Support Battalion, Marine Corps Installations West-Marine Corps Base Camp Pendleton and assumed duties as Company First Sergeant for Company B.

In January 2020, Sergeant Major Johnson was promoted to his current rank assumed his duties as Squadron Sergeant Major for Marine Fighter Attack Squadron 122. In June 2023, he transferred to Marine Aircraft Group 13 and assumed duties as Group Sergeant Major.

Sergeant Major Johnson's personal awards include the Meritorious Service Medal, Navy and Marine Corps Commendation Medal (3rd award), Navy and Marine Corps Achievement Medal (3rd award), and the Combat Action Ribbon. He earned a Bachelor of Arts in Organizational Management from Ashford University.