Sergeant Major Newcomb enlisted in the Marine Corps on 7 July 1993 and attended Recruit Training at Parris Island, South Carolina. Upon completion of Recruit Training he attended Marine Combat Training at Camp Geiger, North Carolina and Ammunition Technician School at Redstone Arsenal, Huntsville, Alabama.
After completing military occupational school in February 1994 Private First Class Newcomb was assigned to Head Quarters Battalion, Camp Fuji Japan where he served as an ammunition technician at the Camp Fuji Ammunition Supply Point.
In March 1995, Lance Corporal Newcomb was transferred to Ammunition Company, 2d Supply Battalion, 2d Force Service Support Group, Camp Lejeune, North Carolina. In October 1995, Corporal Newcomb deployed with a provisional rifle company as a squad leader with Joint Task Force-160 where the JTF was conducting security operations in the migrant camps in Guantanamo Bay, Cuba.
In December 1997, Sergeant Newcomb was transferred to Battery B, 1st Battalion, 12th Marine Regiment in Kaneohe Bay, Hawaii. While there he served as the Battery Ammunition Chief and the Head Quarters Platoon Sergeant. While assigned to Battery B he participated in multiple combined arms exercises and two unit deployments to Okinawa, Japan.
In January 2001, Staff Sergeant Newcomb transferred to Headquarters Battalion, Marine Forces Pacific, Camp H.M. Smith Hawaii. While there he served in the Marine Forces Pacific Command Center serving as an Assistant Command Duty Officer and the principle briefer for the Commander, Marine Forces Pacific.
In January 2002, Staff Sergeant Newcomb reported to Drill Instructor School, Parris Island, South Carolina. Upon graduation from Drill Instructor School he was assigned to Company E, 2d Recruit Training Battalion. While with Company E he served as a Drill Instructor, Senior Drill Instructor and Series Gunnery Sergeant. He also served as the Recruit Processing Company, Receiving Operations Chief while assigned to Support Battalion.
In March 2005, Gunnery Sergeant Newcomb was transferred to 3d Battalion, 10th Marine (3/10) Regiment, Camp Lejeune, North Carolina for service as the Battalion Ammunition Chief. While assigned to 3/10 he deployed twice in support of Iraqi Freedom. Gunnery Sergeant Newcomb was also selected to serve as the Headquarters Battery First Sergeant while assigned to 3/10.
In July 2008, First Sergeant Newcomb was transferred to 2d Intelligence Battalion for service as the Company First Sergeant for Production and Analysis (P&A) Company. While assigned to P&A Company he deployed again in support of Operation Iraqi freedom from September 2008-April 2009. Upon return from deployment 1stSgt Newcomb was assigned to Production and Analysis Support Company.
In May 2010, First Sergeant Newcomb reported to 1st Battalion, 25th Marine Regiment, Fort Devens Massachusetts for duty as the Inspector-Instructor First Sergeant for Head Quarters and Weapons Company.
Upon promotion to his current rank, Sergeant Major Newcomb was assigned as the Sergeant Major of 2d Supply Battalion from May 2013 to July 2015.
From July 2015-June 2017, SgtMaj Newcomb was assigned as the Squadron Sergeant Major of the VMM-162 “Golden Eagles” and deployed as the Aviation Combat Element Sergeant Major in support of the 26th Marine Expeditionary Unit.
From September 2017 to July 2019, Sergeant Major Newcomb was assigned as Regimental Sergeant Major for Combat Logistics Regiment (CLR) 2. While assigned to CLR 2 he deployed as the MAGTF Sergeant Major for the SPMAGTF Crisis-Response Africa.
On 31 July, 2019 Sergeant Major assumed his current post as Sergeant Major for the 3d Marine Logistics group.
Sergeant Major Newcomb’s personal awards include the Meritorious Service Medal w/ Two Gold Stars, the Navy and Marine Corps Commendation Medal w/ 3 Gold Stars, the Navy and Marine Corps Achievement Medal and the Military Outstanding Volunteer Service Medal.