- ABT Associates, Inc.
- AECF
- Alliance for Children & Families
- Alliance for Justice
- Annie E. Casey Foundation
- Aspen Institute Forum for Community Solutions
- Association of Fundraising Professionals
- Association of Small Foundations
- B Analytics
- B Lab
- BBB Wise Giving Alliance
- Better Evaluation
- Big Lottery Fund
- Bill & Melinda Gates Foundation
- Bolder Advocacy
