- AEGON USA
- AEGON USA, Inc.
- Aera Energy LLC
- Aero Methow Rescue Service
- Aerospace Industries Association
- Aerotex Scientific LLC
- Aetna
- Aetna Hispanic Network
- Aetna Insurance Co.
- Aetna of Weston, Florida
- Aetna Volunteer Council
- Aetna, Inc.
- Affinity Health System
- Affordable Pet Care P.C.
- AFGE Local 3721
- AFL-CIO Unions
- AFLAC
- AFLAC Associate
- AFLAC, Inc.
- African American Chamber of Commerce of Central Florida
- African-American Women's Clergy Association
- Africare
- Afro-American Historical and Genealogical Society
- AftersSix
- Agape Senior
- Agenda USA
- Agfa Corporation
- Agilent Technologies Inc.
- AgilQuest Corp.
- Agilysys
- Agnesian Healthcare - St. Agnes Hospital
- Agriculture Research Service, Wyndmoor
- Aguirre Corporation
- AHN Canonsburg Hospital
- AHN Forbes Hospital
- AHN Grove City
- AHN Jefferson Hospital
- AHN Neighborhood Hospitals
- AHN Saint Vincent Hospital
- AHN West Penn Hospital
- AHN Wexford
- Ahwatukee Foothills YMCA
- AI Group
- Aiken Regional Medical Center
- AIKO
- AIM, Inc.
- Ainahau O Kaleponi Hawaiian Civic Club
- Air Conditioning Contractors of America
- Air Force Association
- Air Force Enlisted Village