| Abbreviation | Definition |
|---|---|
| IWSA | International Water Supply Association |
| IWTA | Idaho Wheelchair Tennis Association |
| IWTA | Iowa Water Trails Association |
| IWTA | Irish Water Treatment Association |
| IYA | Indian Yoga Association |
| IYA | Irish Yoga Association |
| IYA | Iyengar Yoga Association |
| IYSA | Indonesian Young Scientist Association |
| IZA | International Zinc Association |
| JAA | Jackson Academy Association |
| JAA | Japan Aikido Association |
| JAA | Japanese American Association |
| JAA | Jaypee Alumni Association |
| JAA | Jewish Association on Aging |
| JAA | Judge Advocates Association |
| JAA | Judges Athletic Association |
| JAAA | Jamaica Amateur Athletic Association |
| JAAA | Japan Association for Automation Advancement |
| JAAC | Jamaica Awareness Association of California |
| JAAC | Jerusalem Artichoke Association of Canada |