| Indole-3-acetic acid | Academic & Science |
| אגודת האקטוארים בישראל | Academic & Science |
| Israel Association of Actuaries | Academic & Science |
| Integrated Arts Academy | Academic & Science |
| Iodo Acetic Acid | Academic & Science |
| InterAmerican Academy | Academic & Science |
| 2-iodoacetamide | Academic & Science |
| Internal Accounting Association | Accounts and Finance |
| Igarka | Airport Code |
| International Academy of Architecture | Associations & Organizations |
| Institute of Actuaries of Australia | Business |
| International Advertising Association | Business |
| Insurance Auto Auctions | Business |
| Indole Acetic Acid | Chemistry |
| Indiana Apartment Association | Community |
| Indian Association of Alberta | Community |
| Independent Ambulance Association | Community |
| Investment Adviser Association | Community |
| Illinois Arborist Association | Community |
| Interior AIDS Association | Community |
| I Am Alive (emergency system) | Computer and Networking |
| Intel Application Accelerator | Computing |
| Initial Address Acknowledgement | Computing |
| Internet Association of Australia | Computing |
| Istituto d'Asta Autoveicoli | General |
| Internationale Automobil Ausstellung (International Automobile Exhibition) | General |
| Insurrectional Army of America | General |
| I Am Awesome | General |
| Intelligent Aerodynamic Automobile | General |
| Irish Aviation Authority | General |
| Internationale Automobil Ausstellung | General |
| Impact Acceleration Accounts | General |
| Interrupted Aortic Arch | General |
| Intensive Action Area | General |
| Intermediaries Agents and Appointees | General |
| Internationalen Automobil Ausstellung | General |
| Idle Air Adjuster | General |
| Independent A-Arm | General |
| International Automobile Association | General |
| Icelandic Automobile Association | General |
| Italian Automotive Academy | General |
| Independent Automotive Advocates | General |
| Information Affairs Authority | Governmental |
| Imperial Affairs Agency | Governmental |
| Indian Aircraft Act | Governmental |
| Institute of Accountancy Arusha | Governmental |
| Immigration Advisers Authority | Governmental |
| Immigration Assessment Authority | Governmental |
| Israel Airports Authority | Governmental |
| Israel Antiquities Authority | Governmental |
| Indianapolis Airport Authority | Governmental |
| Impact Assessment Agency | Governmental |
| INDARA JN | Indian Railway Station |
| International Academy of Astronautics | International |
| International Association of Art | International |
| International Anaplastology Association | International |
| International Airfreight Associates | International |
| International Association for Assyriology | International |
| International Academy Amman | International |
| International Association of Astacology | International |
| International Achievement Awards | International |
| International Affairs Agency | International |
| International Association for Aerobiology | International |
| International Awards Associates | International |
| International Association for Aesthetics | International |
| Ignorant and Apathetic | Messaging |
| Insurance Application Architecture | Softwares |
| International Aerospace Abstracts | Space Science |
| Indara Junction | Transport & Travel |
