- Allyn Moore Automotive Group
- Alpha Phi Alpha Fraternity - Epsilon Lambda Chapter
- AlphaGraphics Camelback
- Alstom Power
- Alta Bates Summit Medical Center
- Alta Health Institute
- Alta View Hospital
- Alternative Service Concepts, LLC
- Alticor
- Altius Health Plans
- Altria
- Altritech
- Altru Health System
- Aluminum Anodizers Council
- Aluminum Consultants Group, Inc.
- Alvarado Hospital Medical Center
- Alvarion
- Alvin C. York VA Medical Center
- Alvin Community College
- Alzheimer's Association
- Amadeus
- Amalgamated Transit Workers Local 85
- Amana Heating and Air Conditioning
- Amanda Hope Rainbow Angels
- Ambassador Capital Management
- Ambassadors Services Group, Inc.
- Amboy National Bank
- Ambulatory Anesthesia Associates
- AMCO Water Metering Systems
- Amed
- Amelia Island
- America First Credit Union
- America Online-Ogden
- America Voyages
- America's Blood Centers
- America's Community Bankers
- America's Freedom Festival Foundation
- American Academy of Audiology
- American Academy of Cosmetic Surgery
- American Academy of Dermatology
- American Academy of Dermatology
- American Academy of Family Physicians
- American Academy of Medical Administrators
- American Academy of Ministry
- American Academy of Nephrology Pas
- American Academy of Neurology
- American Academy of Orthopaedic Surgeons
- American Academy of Pediatrics
- American Academy of Physician Assistants
- American Agricultural Economics Association