| Abbreviation | Definition |
|---|---|
| NBER | National Bureau of Economic Research |
| NBF | National Book Foundation |
| NBGN | National Botanical Garden of Namibia |
| NBIA | National Business Incubation Association |
| NBLP | Nonprofit Board Leadership Program |
| NBME | National Board of Medical Examiners |
| NBN | Nefesh B'Nefesh |
| NBPC | National Black Programming Committee |
| NBSF | National Book Scholarship Fund |
| NBSSI | National Board for Small Scale Industries |
| NBTCI | New Brunswick Trails Council, Inc. |
| NBTF | National Brain Tumor Foundation |
| NBUF | National Black United Federation |
| NBUF | National Black United Front |
| NBUF | National Black United Fund |
| NBUFC | National Black United Federation of Charities |
| NBUFEF | National Black United Front Educational Fund |
| NCA | Native Cultural Alliance |
| NCAC | National Children's Advocacy Center |
| NCAC | National Coalition Against Censorship |