| Rank | Abbreviation | Meaning |
|---|
| ***** | IARS | Image Archival and Retrieval System
| |
| ***** | IARS | implantable, antimicrobial release system
| |
| ***** | IARS | Image Archive & Retrieval System
| |
| ***** | IARS | Improved Aerial Refueling System
| |
| ***** | IARS | International Association of Religious Studies
| |
| **** | IARS | Intercollegiate Athletics and Recreational Sports
| |
| **** | IARS | Iraqi Amateur Radio Society
| |
| *** | IARS | Integrated Airborne Reconnaissance Strategy
| |
| *** | IARS | Inter Agency Referral System
| |
| *** | IARS | Impact Assesment and Response Strategies
| |
| *** | IARS | International Anaesthesia Research Society
| |
| ** | IARS | International Anesthesia Research Society
| |
| ** | IARS | International Assocition of Research Scholars
| |
| ** | IARS | Institute for Applied Research Services
| |
| ** | IARS | Independent Air Revitalization System
| |
| ** | IARS | Illawarra Amateur Radio Society
| |
| * | IARS | Intermountain Adventure Race Series
| |
| * | IARS | Independent Academic Research Studies
| |
| * | IARS | Iron Age Research Student
| |
| * | IARS | Independent Annual Reviews
| |
| * | IARS | International Agency for Research
| |
| * | IARS | International Air Reserve Symposium
| |
| * | IARS | Intermountain Adventure Racing Series
| |