- Adams County Regional Medical Center
- Adams Memorial Hospital
- Addison Gilbert Hospital
- Addison Visitors Services Dept.
- Adena Health System
- Adena Regional Medical Center
- ADESA Des Moines
- Adira at Riverside Rehabilitation
- Adirondack Health
- Adjustable Fixture Company
- ADL Data Systems, Inc.
- ADM
- ADM Co Oil Refinery
- Administracion de Servicios Medicos ASEM)
- Adonai Networking and Logistics Solutioins
- ADP
- ADP Benefit Services
- Adullam Ministries Inc
- Adult Companion Care
- AdvaMed
- Advance America
- Advance Brands
- Advance Clinical Resources
- Advanced Answers On Demand, Inc.
- Advanced Apparel
- Advanced Business Equipment
- Advanced Cardiology Center
- Advanced Care Hospital of White County
- Advanced Foundations and Advanced Water Proofing
- Advanced Orthopedic Centers
- Advanced Solutions International
- Advanced Solutions International, Inc.
- Advanced Technology Systems Company
- Advantage Behavioral Health Systems
- Advantage Care
- Advantage Chevrolet
- Advent Capital Management
- Advent Christian Village
- AdventHealth
- AdventHealth Altamonte Springs
- AdventHealth Apopka
- AdventHealth Carrollwood
- AdventHealth Celebration
- AdventHealth Central Texas
- AdventHealth Dade City
- AdventHealth Daytona Beach
- AdventHealth DeLand
- AdventHealth East Orlando
- AdventHealth Fish Memorial
- AdventHealth Gordon