| Acivilate, Inc. | Georgia |
| ACK Computing | Vermont |
| Ackerman-Estvold | |
| Acklen Avenue, LLC | Tennessee |
| Ackley Machine Corporation | |
| acKnowledge, LLC | New York |
| ACL Computers | Florida |
| Aclaimant | |
| Aclairo Pharmaceutical Development Group, Inc. | |
| Aclara | Missouri |
| Aclarion | Colorado |
| Aclaris Therapeutics, Inc. | |
| Aclarity, Inc. | |
| Aclass Web Sites | New York |
| Aclid, Inc. | |
| Aclima, Inc. | |
| Aclipse Therapeutics | |
| Aclymate | Colorado |
| ACM Computers | California |
| ACM Global Laboratories | |
| ACM Research, Inc. | California |
| ACM SIGGRAPH | |
| ACM Technologies, Inc. | California |
| Acme Bioscience, Inc. | California |
| ACME Design Co. | Florida |
| ACME Digital Design | California |
| Acme Digital Marketing | |
| Acme Internet Services | Oklahoma |
| Acme Micro Systems, Inc. | California |
| Acme Monaco | |
| ACME PCB Assembly | California |
| Acme Portable Machines, Inc. | California |
| ACME VC | California |
| Acme Web Agency | |
| Acmeware, Inc. | Massachusetts |
| Acnodes Corporation | California |
| ACOM Health | Georgia |
| ACOM Solutions | California |
| Acommerce, Inc. | North Carolina |
| Acon Investments, LLC | District of Columbia |
| ACON Laboratories, Inc. | California |
| Aconcagua Ventures, LLC | California |
| Acopian Technical Company | Pennsylvania |
| Acordex Imaging Systems | Massachusetts |
| Acorn Design Studio | |
| Acorn Digital Marketing | |
| Acorn Digital Strategy | California |
| Acorn Recording Solutions, Inc. | New Hampshire |
| Acorns Grow, Inc. | California |
| Acoru | |