| IAMM | International Association of Medical Museums |
|---|---|
| IAMS | International Association of Microbiological Societies |
| IAO | immediately after onset; intermittent aortic occlusion; International Association of Orthodontists |
| IAOM | International Association of Oral Myology |
| IAPB | International Association for Prevention of Blindness |
| MIU | Million International Units |
|---|---|
| OIE | Office International des Epizooties |
| SLICC/ACR | Systemic Lupus International Collaborating Clinics/American College of Rheumatology |
| UICC | Union International Contre le Cancer |