| Abbreviation | Definition |
|---|---|
| ISMH | Institute for Sexual Minority Health |
| ISMI | Idaho Sports Medicine Institute |
| ISMI | International Security Management Institute |
| ISMM | Institute of Sales and Marketing Management |
| ISMM | Institute of Sales Marketing Management |
| ISMP | Institute of Safe Medication Practice |
| ISMR | Institute of Safety Management and Research |
| ISMS | Institute Student Management System |
| ISMS | Institution of Silly and Meaningless Sayings |
| ISMS | Institution of Silly Meaningless Sayings |
| ISMSS | Institute for Sexual Minority Studies and Services |
| ISMSS | Institute of Strategic Management of Social Systems |
| ISN | Institute For Soldier Nanotechnologies |
| ISNI | Illinois Summer Neuroscience Institute |
| ISNT | Institute for the Study of the Neurologically Typical |
| ISNW | Institute for Stewardship of the Natural World |
| ISOF | Institute for Schools of the Future |
| ISPA | Institute of Science and Public Affairs |
| ISPC | Institute for Safety in Powerline Construction |
| ISPD | Institute for School and Parish Development |