Master Gunnery Sergeant Hartman enlisted in the Marine Corps and reported to Marine Corps Recruit Depot San Diego, California in 2002 for recruit training. Upon completion of Aviation Ordnance School, MCAS Cherry Point, North Carolina he received the MOS of 6541 and was assigned to MALS 29, MCAS New River, North Carolina. In 2004, he deployed to Port Au Prince, Haiti with the Air Contingency MAGTF and was promoted to the rank of Corporal.
In 2005, he was deployed with the 26th Marine Expeditionary Unit on the LHD3 USS Kearsarge and he was promoted to the rank of Sergeant. In 2006, he deployed with Marine Aviation Logistics Squadron 16 Reinforced to Al Asad, Iraq in support of Operation IRAQI Freedom. In 2008, he deployed with the 26th Marine Expeditionary Unit a second time to Kandahar, Afghanistan and Forward Operating Base Dwyer in support of Operation Enduring Freedom.
In May 2009, he reported to Recruiter school, Marine Corps Recruit Depot, San Diego, California, where he gained the Billet MOS of 8411.
In July 2009, he reported to Recruiting Station Indianapolis, Indiana, Recruiting Sub Station Southeast Indianapolis where he would serve as a canvassing recruiter, where he was promoted to Staff Sergeant. In June 2010, he checked into Recruiting Sub Station Terre Haute, Indiana, where he would serve as the SNCOIC. In January 2012, he reported to Career Recruiter Course, Marine Corps Recruit Depot, San Diego, California, where he gained the primary MOS 8412.
In February 2012, he reported to Recruiting Sub Station Columbus, Indiana, where he would serve as the SNCOIC and he was promoted to the rank of Gunnery Sergeant. In June 2014, he reported to the Recruiting Station Indianapolis, Indiana Headquarters where he would serve as the Operations Chief and Assistant Recruiting Instructor. In November 2016, he reported to Recruiting Sub Station New Castle, where he would serve as the SNCOIC.
In April 2017, he reported to Recruiting Station Des Moines, Iowa, Recruiting Sub Station, Quad Cities, where he would serve as the SNCOIC and he was promoted to the rank of Master Sergeant.
In October 2018, he reported to Recruiting Station San Diego, California, Recruiting Sub Station, Pearl City, where he would serve as the SNCOIC. In October 2019, he reported to Recruiting Sub Station, Honolulu, where he would serve as the SNCOIC.
In August 2020, he reported to Recruiting Station Seattle, Washington headquarters where he would serve as the Assistant Recruiting Instructor, MEPS liaison and Recruiting Instructor.
In March 2022, he reported to Recruiting Station Albuquerque, where he currently serves as the Recruiting Instructor. In February 2023 he was promoted to the rank of Master Gunnery Sergeant.
Master Gunnery Sergeant Hartman's personal awards include the Meritorious Service Medal, Navy and Marine Corps Commendation Medal (with 2 gold stars), and Navy and Marine Corps Achievement Medal (with 1 silver star).