| Abbreviation | Definition |
|---|---|
| INS | Infusion Nurses Society |
| INTI | Instituto Nacional de Technologia Industrial |
| INTOSAI | The International Organisation of Supreme Audit Institutions |
| IoAb | Independent Online Bookselleers Association |
| IOBC | Israel Organizational Behavior Conference |
| IOD | Institute Of Directors |
| IODI | Institute Of Directors Ireland |
| IODZ | Institute Of Directors Zimbabwe |
| IOM | Institute Of Medicine of the National Academies |
| IONC | International Organization of Nutritional Consultants |
| IOP | International Organization of Paleobotany |
| IOPD | International Organisation of Professional Drivers |
| IOS | Indian Orthodontic Society |
| IOS | Institute of Ocean Sciences |
| IOSCO | International Organisation Of Securities Commissions |
| IOSH | Institute Of Safety and Health |
| IOSM | Institute Of IT (Information Technology) Service Management |
| IOSM | Institute of Safety Management |
| IOTA | International Occultation Timing Association |
| IPA | Independent Physician's Association |