SgtMaj Jernigan is a native of Gates County, NC. He graduated from Gates County High School in May 2002, enlisting in the Marine Corps in June 2002.
After graduating from recruit training at MCRD Parris Island, SC, Private Jernigan proceeded to Camp Geiger, N.C, for Marine Combat Training (MCT). After completing MCT, he reported to Ft. Sill, Ok for training as an 0811 Field Artillery Canoneer. Upon completion of training at Ft. Sill, PFC Jernigan received orders to Bravo Battery 1st Bn., 12th Marines in Kaneohe Bay, HI.
Upon reporting to Bravo Battery he was assigned to Guns Platoon where he served from 2002 until 2006. During this time he completed two rotations as part of the Unit Deployment Program with the Battery to Okinawa, Japan.
In 2006, Sergeant Jernigan conducted a lateral move to become a 0861 Scout Observer. Upon completion of MOS school he was assigned to 10th Marines. He was subsequently assigned to the 22d Marine Expeditionary Unit to serve as the assistant fires chief where he deployed until March of 2008.
In March 2008 Staff Sergeant Jernigan was assigned to 1st Battalion 10th Marines where he served as the assistant battalion Liaison Chief until December of 2008.
In December 2008, Staff Sergeant Jernigan was assigned to 1st Brigade Platoon 2d Air Naval Gunfire Liaison Company where he served as Supporting Arms Liaison Team Chief, and a Brigade Platoon Sergeant. During this time he completed two combat deployments in support of Operation Enduring Freedom.
In Jan 2012, Staff Sergeant Jernigan was assigned to 2d Force Reconnaissance Company, II Marine Expeditionary Force to serve as the Fires Chief and Joint Terminal Attack Controller Instructor & Evaluator. During this time he completed the Marine Aviation and Weapons Squadron One's Air Officer Course.
In July of 2013, Gunnery Sergeant Jernigan was assigned to 1st Marine Special Operations Support Battalion as the Fires Chief and Joint Terminal Attack Controller Instructor until January 2016.
In February of 2016 First Sergeant Jernigan reported to 3d Battalion 2d Marines where he served as the Company First Sergeant for Lima Company until March 2017. During this time he completed a unit deployment to Okinawa, Japan. In March of 2017 he was subsequently reassigned as the Headquarters and Service Company First Sergeant where he completed another deployment with the battalion to Okinawa, Japan.
In March of 2019 First Sergeant Jernigan reported to 8th Communication Battalion as the Service Company First Sergeant until May 2020 when he was reassigned as the Headquarters Company First Sergeant.
Sergeant Major Jernigan was promoted to his current rank on 19 February 2021 and assigned to 3rd Battalion 7th Marines were he now serves.
Sergeant Major Jernigan's personal decorations include the Bronze Star with combat V, Meritorious Service Medal, Navy Commendation Medal with V and two gold stars, Navy and Marine Corps Achievement Medal, and the Combat Action Ribbon.