| Abbreviation | Definition |
|---|---|
| NAM | National Agency for Medicines |
| NARB | National Advertising Review Board |
| NARMS | National Antimicrobial Resistance Monitoring System |
| NAS | National Academy of Sciences |
| NAS | National Asthma Survey |
| NAS | New Active Substance |
| NASAR | National Association of Search and Rescue |
| NASS | National Agricultural Statistics Service |
| NAT | Nucleic Acid-based Tests |
| NATAG | North American Technical Advisory Group |
| NBAC | National Bioethics Advisory Commission |
| NBCS | National Biomedical Computer System |
| NBDRC | National Blood Data Resource Center |
| NBII | National Biological Information Infrastructure |
| NBS | National Bureau of Standards |
| NC | Non-Clinical |
| NCAB | National Cancer Advisory Board |
| NCBA | National Cattlemen's Beef Association |
| NCBDDD | National Center on Birth Defects and Developmental Disabilities |
| NCBI | National Center for Biotechnology Information |