| Abbreviation | Definition |
|---|---|
| NRBA | National REO Brokers Association |
| NRBA | Northern Rockies Blacksmith Association |
| NRCA | National Roofing Contractors Association |
| NRCP | National Respite for Carers Program |
| NRDS | National Realtor Database System |
| NREP | Network for Research on Experiential Psychotherapies |
| NRLA | Northeastern Retail Lumber Association |
| NRMCA | National Ready Mixed Concrete Association |
| NRN | Neonatal Research Network |
| NRSRO | Nationally Recognized Statistical Rating Organization |
| NRT | Nutrition Response Testing |
| NSA | National Sanitary Association |
| NSA | National Sanitation Association |
| NSA | National Security Association |
| NSA | National Skateboard Association |
| NSA | National Slag Association |
| NSA | National Snipers Association |
| NSA | National Stone Association |
| NSA | Northshore Surfing Association |
| NSAPE | North American Society for Pacing and Electrophysiology |