| Chemical Safety Topical Committee | Academic & Science |
| College Soccer Training Center | Academic & Science |
| Charles Schwab Trust Company | Business |
| China Shipbuilding Trading Company | Business |
| California Society Of Tax Consultants | Business |
| Calcutta State Transport Corporation | Business |
| California Safety Training Corporation | Business |
| Committeechemical Safety Topical Committee | Community |
| Crofton Swim and Tennis Club | Community |
| Colorado Springs Track Club | Community |
| Cyber Security Transformation Chef | Computing |
| Cyber Security Training Conference | Computing |
| Cyber Security Training Center | Computing |
| Center For Science And Technology Commercialization | Computing |
| Computer Science Teaching Center | Computing |
| Computer Science Tutoring Center | Computing |
| Computer Security Technology Center | Computing |
| Central Student Technology Committee | Computing |
| Cortico Striatal Thalamo Cortical | General |
| Construction Skills Training Center | General |
| Club Scion Tc | General |
| Construction Skills Training Centre | General |
| Cadet Summer Training Centres | General |
| Customer Service Training Collaborative | General |
| Carl Small Town Center | General |
| Combined Security Transition Command | General |
| Child Study and Treatment Center | General |
| Construction Skills | General |
| Carotid Stenosis Trialists Collaboration | General |
| Crushed Surfacing Top Coarse | General |
| Cost Sensitive Tree of Classifiers | General |
| Counseling Solutions Treatment Centers | General |
| China Shipbuilding Trading Co | General |
| Consolidated Space Test Center | General |
| Concentrator Standard Test Conditions | General |
| Customer Service Training Center | General |
| ContractChild Study Treatment Center | General |
| Complete Streets Transportation Commission | Governmental |
| Consolidated Satellite Test Center | Governmental |
| Carrier Sekani Tribal Council | Governmental |
| Complete Streets and Transportation Commission | Governmental |
| Confédération Syndicale des Travailleurs de Centrafrique | International |
| Confédération Syndicale des Travailleurs du Congo | International |
| Corporate Specialist Training Committee | Medical |
| Children's Speech Therapy Center | Medical |
| Clinical Skills Training Center | Medical |