| Abbreviations | Meaning |
 | IQOLA | International Quality Of Life Assessment |
 | IQWIG | Institut Für Qualität Und Wirtschaftlichkeit Im Gesundheitswesen. Institute For Quality And Efficiency In Health Care |
 | IRA | Institut De Radiophysique Appliquée |
 | IRB | Institutional Review Board |
 | IRB | International Register On Biosafety |
 | IRCAD | Institut De Recherche Contre Les Cancers De L'Appareil Digestif |
 | IRCT | International Rehabilitation Council For Torture Victims |
 | IRDES | Institut De Recherche Et Documentation En Économie De La Santé [Previously: CREDES] |
 | IREB | Institut De Recherches Scientifiques Sur Les Boissons |
 | IRECA | International Rescue And Emergency Care Association |
 | IRH | Institute For Reproductive Health |
 | IRIDE | Inventory Of Resources For Infectious Diseases In Europe |
 | IRIS | Integrated Risk Information System [database] |
 | IRLSSG | International Restless Legs Syndrome Study Group |
 | IRM | HCFA's Information Resources Management Plan |
 | IRMEF | Institut Régional De La Mère, De L'Enfant Et De La Famille |
 | IRMO | Information Resources Management Office (CDC) |
 | IRMVS | Institute For Reparative Medicine And Vascular Surgery |
 | IRPA | International Radiation Protection Association |
 | IRPA | International Retinitis Pigmentosa Association |
 | IRPTC | International Register Of Potentially Toxic Chemicals |
 | IRS | Illinois Radiological Society |
 | IRSA | International Radiosurgery Support Association |
 | IRSA | International Rett Syndrome Association |
 | IRSC / CIHR | Instituts De Recherche En Santé Du Canada / Canadian Institutes Of Health Research |
 | IRSN | Institut De Radioprotection Et De Sûreté Nucléaire |
 | IRSQ | Internet Reference Services Quarterly |
 | IRSSTQ | Institut De Recherche En Santé Et Sécurité Du Travail Du Québec |
 | ISA | International Society Of Andrology |
 | ISA | International Society Of Audiology |
 | ISA | International Stuttering Association |
 | ISA | Irish Stammering Association |
 | ISAAC | International Society For Augmentative And Alternative Communication |
 | ISAC | International Society For Analytical Cytology |
 | ISACCD | International Society For Adult Congenital Cardiac Disease |
 | ISAD | International Society Of Abortion Doctors |
 | ISAD | International Stuttering Awareness Day |
 | ISAKOS | International Society Of Arthroscopy, Knee Surgery, And Orthopaedic Sports Medicine |
 | ISAM | International Society For Aerosols In Medicine |
 | ISAP | International Society For Anaesthetic Pharmacology |
 | ISAP | Internet Self-Assessment In Pharmacology |
 | ISAPA | International Society For Aging And Physical Activity |
 | ISARS | Institut Fédératif Saint-Antoine De Recherche Sur La Santé |
 | ISB | International Society Of Biomechanics |
 | ISB / SIB/ SIB | Institut Suisse De Bioinformatique / Schweizerisches Institut Für Bioinformatik / Swiss Institute Of Bioinformatics |
 | ISBM | International Society Of Behavioral Medicine |
 | ISBOR | International Society Of Breath Odor Research |
 | ISBP | International Society Of Blood Purification |
 | ÏSBS | International Society For Biophysics And Imaging Of The Skin |
 | ISBS | International Society Of Biomechanics In Sports |