| NNHS | National Nursing Home Survey |
|---|---|
| NNI | noise and number index |
| NNIS | National Nosocomial Infections Study |
| NNM | neonatal mortality |
| NNMC | National Naval Medical Center |
| NNN | Novy-MacNeal-Nicolle [medium] |
| NNNMU | N-nitroso-N-methylurethane |
| NNO | no new orders |
| NNP | neonatal nurse practitioner; nerve net pulse |
| NNR | New and Nonofficial Remedies |