- National Council on Aging
- National Fire Protection Association
- National Governors Association
- National Guard
- National Health Investors
- National Health Investors Inc.
- National Healthcare Corporation
- National Healthcare Development
- National Healthcare Safety Network
- National Institute for CNA Excellence
- National Institute on Aging
- National Institutes of Health
- National Investment Center for Seniors Housing & Care
- National Investment Center for Seniors Housing and Care
- National Investment Centers for
- National Nurses United
- National Opinion Resource Center
- National Poll on Healthy Aging
- National Rural Health Association
- National Senior Service Corps.