| Abbreviation | Definition |
|---|---|
| NASS | National Ankylosing Spondylitis Society |
| NASS | National Association of Street Schools |
| NASS | National Asylum Support Services |
| NASS | North American Spine Society |
| NASS | North American Squirrel Society |
| NASVF | National Association of Seed and Venture Funds |
| NATE | National Association of Teachers of English |
| NATEF | National Automotive Technicians Education Foundation |
| NATP | National Association of Tax Professionals |
| NATSO | National Association of Truck Stop Operators |
| NATT | National Alliance for Thrombosis and Thrombophilia |
| NAVI | North Area Volunteer Initiative |
| NAVMIL | The Navigators |
| NAVP | National Anti-Violence Project |
| NAVS | National Anti-Vivisection Society |
| NAVS | North American Vegetarian Society |
| NAW | Network for Asian Workers |
| NAWA | National Avian Welfare Alliance |
| NAWB | Not a Wife Beater |
| NAWHO | National Asian Women's Health Organization |