Sergeant Major Cartmill enlisted in the Marine Corps on January 16th, 1990 from Garden City, Kansas and reported to Marine Corp Recruit Depot (MCRD) San Diego California for recruit training. He was assigned to Fox Company, 2nd Recruit Training Battalion.

After graduating from MCRD San Diego California, PVT Cartmill was assigned the military occupation specialty of Organizational Automotive Mechanic (3521). He reported to the Motor Transport School at Camp Johnson, Camp Lejeune, North Carolina. After graduating Motor Transport School, PFC Cartmill reported to 3rd Tank Battalion, Twentynine Palms, CA serving as a Motor Transport mechanic.

In August 1993, Corporal Cartmill reported to Motor Transport Maintenance Company, 3rd Maintenance Battalion, 3d Force Service Support Group, Okinawa Japan and served as Contact Team Leader and Contact Team Chief.

In August 1994, Sergeant Cartmill returned to the U.S. and reported to Detachment A, 1st Surveillance Reconnaissance and Intelligence Group, 1st MEF Headquarter Group, Twentynine Palms California. He was assigned as Motor Transport and Utilities Shop Chief In 1996 Sergeant Cartmill deployed to Bosnia-Herzegovina While is support of Operation Joint Endeavor, Task Force Eagle.

In July 1997, Sergeant Cartmill transferred to Marine Wing Communications Squadron-28, 2nd Marine Air Wing, Marine Corps Air Station Cherry Point, North Carolina. He served as Platoon Sergeant and Shop Chief. Sergeant Cartmill was promoted to Staff Sergeant in March 1998 and then reassigned to VMU-2, 2nd Marine Air Wing, Marine Corps Air Station Cherry Point, North Carolina, where he served as the Motor Transport Maintenance Chief.

Staff Sergeant Cartmill was then ordered to recruiter school in October 2000 and assigned to Recruiting Station Sacramento, CA where he served as a canvassing recruiter, Recruiting Sub Station Visalia, CA from January 2001 to June 2002. He was then reassigned Staff Noncommissioned Officer in Charge, Recruiting Sub Station Reno, NV and subsequently promoted to gunnery sergeant in October 2002. While assigned to RSS Reno Gunnery Sergeant Cartmill was awarded as the RS Sacramento, 12th Marine Corps District, Western Recruiting Region and Marine Corps Recruiting Commands Staff Noncommissioned Officer of the year for FY 03.

In 2004, Gunnery Sergeant Cartmill was transferred to 3rd Radio Battalion, 3rd MEF Headquarters Group, MCB Hawaii where he served as the Motor Transport Chief from January 2004 until January 2005 and then as the Headquarters and Service Company First Sergeant from January to April 2005. He then served as the Logistics Chief and deployed with the battalion to Iraq in support of Operation Iraqi Freedom 04-06 from May 2005 to March 2006.

First Sergeant Cartmill was promoted in June 2006 and was assigned as the Company First Sergeant, Headquarters and Service Company, 1st Light Armored Reconnaissance Battalion. While assigned to Headquarters and Service Company, he deployed to Iraq in support of Operation Iraqi Freedom 06-08 from March 2007 until September 2007. He then served as the Battalion Sergeant Major from Nov 2007 to March 2008 and as the Company First Sergeant, Company A from March 2008 to May 2009.