| Abbreviation | Definition |
|---|---|
| ISBH | Indiana State Board of Health |
| ISBI | Illinois State Board of Investment |
| ISCI | Idaho State Correctional Institution |
| ISD | Income Support Division |
| ISDA | Idaho State Department of Agriculture |
| ISDS | Initiative for Sub-District Support |
| ISDT | Indiana State Department of Toxicology |
| ISFP | Iowa Strengthening Families Program |
| ISIB | Iowa Summer Institute in Biostatistics |
| ISRA | Industrial Site Recovery Act (New Jersey) |
| ISSCA | Iowa State Saddle Clubs Association |
| ISSOFBC | Immigrant Services Society of British Columbia |
| ISSSTE | Instituto de Seguridad y Servicios Socials de los Trabajadores del Estado |
| ISTC | Idaho State Tax Commission |
| ITC | Information Technology Commission |
| ITEC | Illinois Technology Enterprise Centers |
| ITFA | Indiana Transportation Finance Authority |
| ITOW | Independent Towns Of Washington |
| ITPC | Indiana Tobacco Prevention and Cessation |
| ITSAP | Idaho Telephone Service Assistance Program |