Headquarters and Service battalion provides command and control, administration, communications, security, food service and data processing support to the Marine Logistics Group (MLG) and supporting services to the Marine Expeditionary Force (MEF) or two Marine Expeditionary Brigades (MEB) and MEF residual forces in expeditionary/amphibious operations and subsequent operations ashore. Support includes data processing, financial disbursing, postal, legal, Marine Corps Exchange (MCX) and consolidated Navy personnel administration to the MLG. The battalion typically consists of headquarters company, communications company, military police company, and service company.