In 1965, Major General Joe M. Ernst was commissioned as a Quartermaster Officer through the Reserve Officers Training Corps at Texas A&M University.  Following the Quartermaster officers basic Course, he deployed to Vietnam for 15 months. Following his service in Vietnam, Major General Ernst returned to San Antonio Texas to begin his civilian career and service in the Army Reserves.

Major General Ernst has served in the following Key command and Staff positions during assignments over a 30 year career, including nearly 13 consecutive years in Command and Deputy Command Billets:  Assistant Deputy Commanding General (IMA) for Reserve Affairs, Army materiel Command, Alexandria, Virginia, Commander, 377^th theater Army Area Command, New Orleans, Louisiana, Commander, 125^th United States Army reserve Command, Nashville, Tennessee, Deputy Commanding General, 90^th United States Army Reserve Command, San Antonio, Texas, Deputy Commander 377^th Theater Army Area Command, New Orleans, Louisiana, Commander, 363d Support Group, San Marcos, Texas, Deputy Chief of Staff, Resource Management, 90^th United States Army Reserve Command, San Antonio, Texas,  Assistant Chief of Staff, 90^th United States Army Reserve Command, San Antonio, Texas.

Major General Ernst  awards and decorations include the Army Distinguished Service Medal (with Silver Leaf Cluster), Legion of Merit (with Oak Leaf Cluster), the Bronze Star, the Meritorious Service Medal (with Silver Leaf Cluster), the National Defense Service Medal, the Vietnam Service Medal (with 4 Campaigns), the Armed Forces Service Medal (with 10 Year Device), the Army Service Ribbon, the Global War on Terrorism Medal, Republic of Vietnam Campaign Medal, Meritorious Unit Citation, Republic of Vietnam Unit Gallantry Cross with Palm. 

Major General Ernst is a graduate of the following military schools/courses: 

Quartermaster Officer Basic Course, Basic Procurement Course, Quartermaster Officer Advanced Course, U.S. Army Command and General Staff College, Air War College, Army War College, Senior reserve Component Officer Course, Harvard University Program for Senior Executives in National Security.

In his civilian capacity, Major General Ernst currently serves as Director, Marketing Department, H.E. Butt Grocery Company, San Antonio, Texas, President and Owner, real Estate Enterprises, San Antonio Texas.  His responsibilities include management oversight for both Companies with more than 48,000 employees and more than $7.5 Billion in annual sales.