| American College Application Campaign | Academic & Science |
| ACAC Of course Alberta Colleges | Academic & Science |
| Colombian Association for the Advancement of Science | Academic & Science |
| Asociación Colombiana para el Avance de la Ciencia | Academic & Science |
| Academic Computing Advisory Committee | Academic & Science |
| Academic and Career Advising Center | Business |
| Academic and Career Advisement Center | Business |
| Arkansas Casino Corporation | Business |
| Agree, Confirm, Answer, and Close | Business |
| American Council for Accredited Certification | Business |
| Atlanta Competitive Advantage Conference | Community |
| Ames Cyclone Aquatics Club | Community |
| Atomic City Aquatic Club | Community |
| Alberta College Athletic Conference | Community |
| Allegheny Center Alliance Church | Community |
| Allied Churches of Alamance County | Community |
| Allied Churches of Alamance | Community |
| Austin Creative Art Center | Community |
| Adria Commission for Arts Culture | Community |
| Atlanta Community Access Coalition | Community |
| Association for Child and Adolescent Counseling | Community |
| Abbreviations Com Academic Computing | Computing |
| Academic Computing Advisory Council | Computing |
| Allen Chapman Activity Center | General |
| Atlanta Competitive | General |
| Atlanta Competitive Advantage | General |
| Atlanta Contemporary Art Center | General |
| Acetylacetone ACAC Acetoacetate ACAC | General |
| Another Choice Another Chance | General |
| Athens Cultural Affairs Commission | General |
| Air Conditioning At Cost | General |
| AVIC i Commercial Aircraft Company | General |
| Always Clean Air Cabin | General |
| Auto Credit Assistance Corporation | General |
| Association Champenoise des Automobiles de Collection | General |
| Automobile Club Andre Citroen | General |
| A Cappella Advisory Council | Governmental |
| All a Cappella Auditions Council | Governmental |
| acetoacetic acid | Medical |
| acetyl-coenzyme A cocarboxylase | Medical |
| Area Clinical Audit Committee | Medical |
| Amador County Arts Council | Regional |
| Allen County Athletic Conference | Regional |
| Alberta Colleges Athletics Conference | Sports |
| Atlantic Coast Athletic Club | Sports |
