The 63rd Regional Support Command is responsible for the base and administrative support of all United States Army Reserve units throughout the seven-state region of southwestern United States including California, Nevada, Arizona, New Mexico, Oklahoma, Texas and Arkansas. Although the 63rd Regional Readiness Command located in Los Alamitos, CA, was not authorized to carry the lineage of the 63rd Infantry Division, the creation of the new 63rd Regional Support Command in Moffett Field, CA, authorizes it to inherit the lineage and the bi-color red and blue background 63rd Infantry Division flag as an exception to policy. The unit was inactivated on 6 December 2009 and replaced by the 79th Sustainment Support Command, and was reactivated as a regional support command.