American Chemical Society 
Advisory Circulars 
Advanced Camera for Surveys 
Attitude Control System 
Aerial Common Sensor 
American Cancer Society 
Automated Commercial System 
Army Community Service 
Attitude Control Subsystem 
American College of Surgeons 
Australian Computer Society 
Access Control Server 
Access Control System 
Advanced Communications System 
American Community Survey 
Antenna Control System 
Acute Coronary Syndrome 
Automated Collection System 
Aegis Combat System 
Affiliated Computer Services 
Afloat Correlation System 
Air Control Squadron 
Army Commmuity Service 
Atmosphere Control and Supply 
Australian Computer Science 
Auxiliary Crane Ship 
Address Change Service 
Agile Combat Support 
Air Combat Systems 
American Citizen Services