| IAGUS | International Association of Genito-Urinary Surgeons |
|---|---|
| IAHS | infection-associated hemophagocytic syndrome; International Association of Hospital Security |
| IAMM | International Association of Medical Museums |
| IAMS | International Association of Microbiological Societies |
| IAO | immediately after onset; intermittent aortic occlusion; International Association of Orthodontists |