| Abbreviation | Definition |
|---|---|
| IAS | International Association of Sedimentologists |
| IASA | India Association of San Antonio |
| IASAP | International Association for the Study of Attention and Performance |
| IASAP | International Association of Security |
| IASB | Illinois Association of School Boards |
| IASB | Indiana Association of School Broadcasters |
| IASB | International Association |
| IASB | International Association of Speakers Bureaus |
| IASB | Iowa Association of School Boards |
| IASC | Illinois Association of Student Councils |
| IASC | Indiana Association of Student Councils |
| IASC | International Association for the Study of Controversies |
| IASC | International Association for the Study of the Commons |
| IASCA | Idaho Ambulatory Surgery Center Association |
| IASCA | Irish Association of Songwriters Composers And Authors |
| IASCP | International Association for the Study of Common Property |
| IASE | International Association for Special Education |
| IASH | International Association for Small Hydro |
| IASH | International Association for the Stability and Handling |
| IASI | International Association of Structural Integrators |