| International Students for Environmental Action | Academic & Science |
| Iowa State Education Association | Academic & Science |
| International Student Exchange Association | Academic & Science |
| International Society of Exposure Analysis | Academic & Science |
| Inter Society for the Electronic Arts | Academic & Science |
| International Symposium for Electronic Arts | Academic & Science |
| Integrated Support Engineering Agent | Academic & Science |
| Industrial Safety Equipment Association | Business |
| Int'l Space Exploration Agency | Business |
| International Society for Exposure Analysis | Community |
| International Symposium on Electronic Art | Community |
| Indiana Student Education Association | Community |
| International Safety Equipment Association | Community |
| Irish Solar Energy Association | Community |
| International Sports Engineering Association | Community |
| Independent Schools Education Association | Community |
| International Software Escrow Association | Community |
| International Statistical Engineering Association | Community |
| Independent Special Education Advice | Community |
| Institute of Special Education Advocacy | Community |
| Inland Seas Education Association | Community |
| Illinois Solar Energy Association | Community |
| Island South-East Asia | General |
| Institute for Social and Economic Analyses | Governmental |
| International Sustainable Energy Assessment | Governmental |
| Institute for Spatial Economic Analysis | Governmental |
| International Society of Experimental Artists | International |
| International Society of Electronica Arts | International |
| Icosahedral Snyder Equal Area | Maths |
| In Service Engineering Agent | Military and Defence |
| Information Security Education and Awareness | Ministry of Communications and Information Technology |
