| Abbreviation | Definition |
|---|---|
| IMNF | Institute for Music and Neurologic Function |
| IMO | Into Members Only |
| IMPACT | Incorporation to Maximize Personal Achievement with Community Training |
| IMPD | Institute For Multi Party Democracy |
| IMS | Institute for Medical Statistics |
| IMSFF | Injured Marine Semper Fi Fund |
| IMT | Independent Music Teachers |
| IMT | Institute for Market Transformation |
| IMY | Indira Mahila Yojana |
| INAS | Institute of Native American Studies |
| INCD | International Network for Cultural Diversity |
| INCOSE | International Council on Systems Engineering |
| IND | Inaudible Noise Distortion |
| INDIE | Integrated Network of Disability Information and Education |
| INE | Institute of Northern Engineering |
| INEE | Inter-Agency Network for Education in Emergencies |
| INFE | International Newspaper Financial Executives |
| INFORMS | Institute for Operations Research and the Management Sciences |
| INGHA | It's Not Gonna Happen Anymore |
| INGO | International Non-Governmental Organization |