| Abbreviations | Meaning |
 | NAR | Nasal Airway Resistance; National Association For Retarded [Children, Citizens]; No Action Required |
 | NARA | Narcotics Addict Rehabilitation Act; National Association Of Recovered Alcoholics |
 | NARC | Narcotic; National Association For Retarded Children; Nucleus Arcuatus |
 | NARCF | National Association Of Residential Care Facilities |
 | NARD | National Association Of Retail Druggists |
 | NARF | National Association Of Rehabilitation Facilities |
 | NARMH | National Association For Rural Mental Health |
 | NARS | National Acupuncture Research Society |
 | NAS | National Academy Of Sciences |
 | NAS | National Association Of Sanitarians |
 | NAS-NRC | National Academy Of Science-National Research Council |
 | NASD | National Association Of Schools Of Dance |
 | NASE | National Association For The Study Of Epilepsy |
 | NASEAN | National Association For State Enrolled Assistant Nurses |
 | NASPE | North American Society For Pacing And Electrophysiology |
 | NASPE/BPEG | North American Society Of Pacing And Electrophysiology [NASPE]-British Pacing And Electrophysiology Group [BPEG] Pacemaker Coding |
 | NASPEM | North American Society For Pediatric Exercise Medicine |
 | NASS | North American Spine Society (also: AAOS Related Organizations) |
 | NASS | National Accident Sampling System; North American Spine Society |
 | NASW | National Association Of Social Workers |
 | NATA | National Athletic Trainers Association |
 | NAVAPAM | National Association Of Veterans Affairs Physician Ambulatory Care Managers |
 | NBCC | National Board Of Certified Counselors; Nevoid Basal Cell Carcinoma |
 | NBCOT | National Board For Certification In Occupational Therapy |
 | NBME | National Board Of Medical Examiners; Normal Bone Marrow Extract |
 | NBOME | National Board Of Osteopathic Medicine Examination |
 | NBPME | National Board Of Podiatric Medicine Examiners |
 | NBRT | National Board For Respiratory Therapy |
 | NCRA | National Cancer Registrars Association (USA) |
 | NCSBN | National Council Of State Boards Of Nursing |
 | NDA | National Dental Association |
 | NDSB | Narcotic Drugs Supervisory Board |
 | NEMA | National Eclectic Medical Association |
 | NESO | Northeastern Society Of Orthodontists |
 | NFA | National Fire Academy; Near-fatal Asthma; Nuclear Factor A |
 | NFRA | National Fibromyalgia Research Association (US) |
 | NHA | National Health Association |
 | NHA | National Hearing Association |
 | NHA | National Hemophilia Association |
 | NHB | National Health Board |
 | NHLA | National Health Lawyers Association |
 | NINCDS/ADRDA | National Institute Of Neurological And Communicative Diseases And Stroke/Alzheimer's Disease And Related Disorders Association |
 | NIRB | Non-institutional Review Board |
 | NKCA | National Kidney Cancer Association (USA) |
 | NLA | National Leukemia Association; Neuroleptoanesthesia; Normal Lactase Activity |
 | NM(ASCP) | Technologist In Nuclear Medicine Certified By The American Society Of Clinical Pathologists |
 | NMA | National Malaria Association; National Medical Association; Neurogenic Muscular Atrophy; N-nitroso-N-methylalanine |
 | NMHCA | National Mental Health Consumers' Association |
 | NMSS | National Multiple Sclerosis Society |
 | NMSS | National Multiple Sclerosis Society; National Mycobacterial Surveillance System [Australia And New Zealand] |