- Abrazo Central Campus
- Abrazo Health
- Abrazo Scottsdale Campus
- Abrazo West Campus
- Abrazo West Campus
- ABVM
- AC Nielsen
- ACA International - The Association of Credit - Collection Professionals
- Academic Management Services
- Academy Corp.
- Academy of Financial Services Studies, LLC
- Academy of Motion Picture Arts and Science
- Acadia General Hospital
- Acadia Parish Police Jury
- Acadian Medical Center
- Accenture
- Access Direct Systems Inc.
- Access II Care
- AccessClosure
- AccessHealth
- ACCG
- Acculogix
- Ace Electric Company Inc.
- ACE Uniform and Services of Virginia Inc.
- ACHCA
- Achieva
- Achieve Healthcare Information Systems
- Achievement Academy, Inc.
- ACM Global Laboratories
- Acme Markets
- ACMH Hospital
- Acordia National
- Acorn Sales Company Inc.
- Acres Home Citizens Chamber of Commerce
- ACS
- ACT Expocad
- Act Like An Owner
- ACT, Inc.
- Acts Retirement Life Communities Inc.
- Actsoft
- Acurian
- Ad+one
- Ada County
- Ada Regional United Way
- Adagio Health Council
- Adair County Health System
- Adair County Memorial Hospital
- Adam's Mark Downtown Dallas
- Adam's Mark Philadelphia
- Adams County Association for the Blind