| Abbreviation | Definition |
|---|---|
| IAPSO | International Association for the Physical Sciences of the Oceans |
| IAPSS | IN Association of Public School Supts |
| IAPSS | Indiana Association of Public School Superintendents |
| IAPSS | International Association of Political Science Students |
| IAPT | International Association for Plant Taxonomy |
| IAPT | International Association for the Philosophy of Time |
| IAPT | Irish Association of Physical Therapists |
| IAR | Islamic Association of Raleigh |
| IARCC | International Association Of Risk And Crisis Communication |
| IARD | International Association for Relativistic Dynamics |
| IARM | Irish Association of Rehabilitation Medicine |
| IARM | Irish Association of Relationship Mentors |
| IARP | Indian Association for Radiation Protection |
| IARP | International Association of Reiki Professionals |
| IARP | International Association of Rock Physicists |
| IARP | Iowa Association of Railroad Passengers |
| IARS | Indian Association for Reliability and Statistics |
| IARS | Irish Association of Respiratory Scientists |
| IART | Indian Association of Radiological Technologists |
| IAS | International Association of Scientology |