| Abstract Technology Group | Indiana |
| Abstraction Consulting Co. | Georgia |
| ABSTRAKT Corporation | Arizona |
| Absyz, Inc. | Michigan |
| Absyz, Inc. | Michigan |
| Abterra Biosciences | California |
| AbTherx | California |
| Abundance Partners, LLC | New York |
| Abundant Computer Services, LLC | Florida |
| Abundant Robotics, Inc. | California |
| Abusix, Inc. | Massachusetts |
| AbVacc | Maryland |
| Abveris | Massachusetts |
| Abyrx, Inc. | |
| ABZ, Inc. | Virginia |
| Abzyme Therapeutics, LLC | Pennsylvania |
| AC Consulting | California |
| AC Lion | New York |
| AC Photonics, Inc. | California |
| AC2, Inc. | Texas |
| ACA Computer Integrators, Inc. | Massachusetts |
| ACA Group | |
| ACA Systems | Minnesota |
| ACA Technologies, Inc. | New Jersey |
| ACA WEB Consulting | California |
| Acacia Communications, Inc. | Massachusetts |
| Acacia Systems | California |
| ACAD-Plus, Inc. | Texas |
| Acadaca | New York |
| Academe Solutions | Maine |
| Academic Software, Inc. | Kentucky |
| Academic Web Pages | Massachusetts |
| AcademicSuperstore.com | Texas |
| Academy Bank, N.A. | |
| Academy Communications | Ohio |
| Academy for Radiology & Biomedical Imaging Research | |
| Academy of Art University | California |
| Academy of Interactive Arts & Sciences | California |
| Academy Pittsburgh, LLC | Pennsylvania |
| Academy Software Foundation | California |
| Academy Systems | New York |
| AcademyX, Inc. | California |
| Acadeus | Montana |
| Acadia Creative, LLC | Maine |
| Acadia Pharmaceuticals, Inc. | California |
| Acadia Systems, Inc. | Pennsylvania |
| Acadia Technology Group, LLC | New Jersey |
| Acadia Technology, Inc. | California |
| Acadiana Computer Systems, Inc | Louisiana |
| Acadiana Security Plus | Louisiana |