- Human Interaction Research Institute
- Innovation Network
- Institute for Voluntary Action Research (IVAR)
- International Monetary Fund
- J. W. McConnell Family Foundation
- James Irvine Foundation
- John S. and James L. Knight Foundation
- Joseph Rowntree Foundation
- Levi Strauss Foundation
- Lloyds Bank Foundation for England and Wales
- Maine Community Foundation
- Marguerite Casey Foundation
- MIT D-Lab
- MIT Practical Impact Alliance
- Monitor Deloitte
- Monitor Institute
- National Committee for Responsive Philanthropy
- NEO Philanthropy
- New Philanthropy Capital (NPC)
- Nonprofit Finance Fund
