| Abbreviation | Definition |
|---|---|
| ILF | International Leadership Foundation |
| ILF | International Legal Foundation |
| ILF | Islamic Learning Foundation |
| ILLF | International Lottery in Liechtenstein Foundation |
| ILLF | Internationale Lotterie in Liechtenstein Foundation |
| ILSCF | Iowa Lions Sight Conservation Foundation |
| IMAF | International Medical Assistance Foundation |
| IMAF | International Music and Art Foundation |
| IMCF | Integrative Medical Clinic Foundation |
| IMEF | International Milling Education Foundation |
| IMF | International Monetary Foundation |
| IMFT | Ingleby Manor Foundation Trust |
| IMMF | International Midway Memorial Foundation |
| IMRF | Iowa Measurement Research Foundation |
| IMSF | International Mars Science Foundation |
| IMSF | International Mass Spectrometry Foundation |
| IMSF | Iowa Medical Society Foundation |
| INFINITY | In Natural Future Incarnation Naturally Identified Terminal Yarn |
| INIF | India Neuro Interventional Foundation |
| INRF | Indiana Natural Resources Foundation |