| Abbreviation | Definition |
|---|---|
| NIMH | National Institute of Medical Herbalists |
| NIOB | Nigerian Institute Of Building |
| NIPA | National Institute of Pension Administrators |
| NIPSA | National Independent Private School Association |
| NIPT | North Idaho Physical Therapy |
| NIQS | Nigerian Institute of Quantity Surveyors |
| NISO | National Information Standards Organization |
| NITL | National Industrial Transportation League |
| NITL | National Institute for Transport Logistics |
| NITL | National Institute for Transport & Logistics |
| NJBA | New Jersey Beekeepers Association |
| NJBA | New Jersey Broadcasters Association |
| NJBA | New Jersey Builders Association |
| NJCAA | National Job Corps Alumni Association |
| NJCAA | National Junior College Athletic Association |
| NJCAA | New Jersey Community Action Association |
| NKAD | Nursery and Kindergarten Association of Delaware |
| NKCA | National Kitchen Cabinet Association |
| NLA | National Leather Association |
| NLA | National Lime Association |