| Abbreviation | Definition |
|---|---|
| IPTA | Illinois Pipe Trades Association |
| IPTA | International Parcel Tankers Association |
| IPTA | International Pediatric Transplant Association |
| IPTA | Iowa Public Transit Association |
| IPTA | Iowa Pupil Transportation Association |
| IPWA | International Private Water Association |
| IPWA | Israeli Pro Wrestling Association |
| IQA | International Quidditch Association |
| IQPA | International Quarter Pony Association |
| IQSA | International Qajar Studies Association |
| IQSA | International Quranic Studies Association |
| IRA | Intercollegiate Rowing Association |
| IRA | Interstate Racing Association |
| IRAA | Imperial Rule Assistance Association |
| IRATA | International Rope Access Trade Association |
| IRBA | International Ripple Business Association |
| IRBA | Ireland Russia Business Association |
| IRCA | Indian Railway Conference Association |
| IRCA | International Ragdoll Cat Association |
| IRCA | Iowa Rodeo Cowboys Association |