| Abbreviation | Definition |
|---|---|
| ISBA | Indiana School Boards Association |
| ISCA | Idaho School Counselor Association |
| ISCA | Idaho School Counselors Association |
| ISCA | Illinois Soil Classifiers Association |
| ISCA | Indiana State Chiropractic Association |
| ISCA | International Safety Coach Association |
| ISCA | International School Counselor Association |
| ISCA | International Seascape18 class association |
| ISCA | International Shrine Clown Association |
| ISCA | International Sport and Culture Association |
| ISCA | International Swim Coaches Association |
| ISCA | International Systemic Constellations Association |
| ISDA | Illinois State Deans' Association |
| ISDA | International Security Driver Association |
| ISDA | International Swap and Derivative Association |
| ISDA | International Swap Dealer Association |
| ISDA | International Swap Dealers Association |
| ISDA | International Swaps and Derivative Association |
| ISDA | Iowa State Dairy Association |
| ISEA | Illinois Solar Energy Association |