| Abbreviation | Definition |
|---|---|
| NSN | Native Sovereign Nation |
| NSO | National Statistical Office |
| NSPP | National School of Public Policy |
| NSQAP | Newborn Screening Quality Assurance Program |
| NSR | Non-Self Regulating |
| NSRF | National Strategic Reference Framework |
| NSRP | National Security Research Project |
| NSS | National Security Service |
| NSS | National Standards System |
| NSS | New Sectional Standard |
| N-SSATS | National Survey of Substance Abuse Treatment Services |
| NSSC | National School Safety Center |
| NSSC | National Security Studies Course |
| NSSC | National Standards Strategy Committee |
| NSSDR | National Sealed Source and Device Registry (U.S. Nuclear Regulatory Commission) |
| NSSN | National Social Security Number |
| NSSN | National Standards Systems Network |
| NSTDPC | National Sexully Transmitted Disease Prevention Confrerece |
| NSTISSC | National Security Telecommunications and Information Systems Security Committee |
| NSTISSD | National Security Telecommunications and Information Systems Security Directive |