| I&T | Integration And Test | - | Business and Finance |
| I&T | Integration And Test | - | Business and Finance |
| I/ O | Input/output | - | Business and Finance |
| I/F | Interface | - | Business and Finance |
| I/O | Input/output | - | Business and Finance |
| I2L | Integrated Injection Logic | - | Business and Finance |
| IA | International Angstrom | - | Business and Finance |
| IAA | International Academy Of Astronautics | - | Business and Finance |
| IAAC | International Antarctic Analysis Center | - | Business and Finance |
| IACOMS | International Advisory Committee On Marine Sciences | - | Business and Finance |
| IAD | Dulles International Airport | - | Business and Finance |
| IADB | Interactive Ancillary Data Base | - | Business and Finance |
| IAEA | International Atomic Energy Agency | - | Business and Finance |
| IAG | International Association Of Geodesy | - | Business and Finance |
| IAG | Interagency Agreement | - | Business and Finance |
| IAG | Instrumentation Advisory Group | - | Business and Finance |
| IAGA | International Association Of Geomagnetism And Aeronomy | - | Business and Finance |
| IAGW | International Acoustic Gravity Waves | - | Business and Finance |
| IAHS | International Association Of Hydrological Sciences | - | Business and Finance |
| IAMAPS | International Association Of Meteorology And Atmospheric Physics Sciences | - | Business and Finance |
| IAMAS | International Association Of Meteorology And Atmospheric Sciences | - | Business and Finance |
| IAP | International Affiliates Program | - | Business and Finance |
| IAPO | International Association Of Physical Oceanography | - | Business and Finance |
| IAPSO | International Association Of Physical Sciences Of The Ocean | - | Business and Finance |
| IARP | International Atmospheric Research Program | - | Business and Finance |
| IAS | Indicated Air Speed | - | Business and Finance |
| IASH | International Association Of Scientific Hydrology | - | Business and Finance |
| IASP | International Atmospheric Surveillance Program | - | Business and Finance |
| IASPEI | International Association Of Seismology And Physics Of The Earth's Interior | - | Business and Finance |
| IATO | Independent Acceptance Test Organization | - | Business and Finance |
| IAU | International Astronomical Union | - | Business and Finance |
| IAV | International Association Of Volcanology | - | Business and Finance |
| IAVCEI | International Association Of Volcanology And Chemistry Of The Earth's Interior | - | Business and Finance |
| IAWSP | Intergrated Aviation Wind Shear Plan | - | Business and Finance |
| IBM | International Business Machines Corporation | - | Business and Finance |
| IBM AT | IBM Advanced Technology Personal Computer | - | Business and Finance |
| IBM PC | Generic Term For IBM Personal Computers | - | Business and Finance |
| IBM PS/2 | One Class Of IBM Personal Computers | - | Business and Finance |
| IBM RT | The IBM RISC Technology Computer System | - | Business and Finance |
| IBRD | International Bank For Reconstruction And Development | - | Business and Finance |
| ICA | International Central Archive | - | Business and Finance |
| ICAMR | Interdepartmental Committee On Applied Meteorological Research | - | Business and Finance |
| ICAO | International Civil Aviation Organization | - | Business and Finance |
| ICAR | International Cooperation In Aviation Research | - | Business and Finance |
| ICAS | Interdepartmental Committee On Atmospheric Science | - | Business and Finance |
| ICAS | Interdepartmental Communication For Atmospheric Science | - | Business and Finance |
| ICC | Instrument Control Center | - | Business and Finance |
| ICCP | International Commission Of Clouds And Precipitation | - | Business and Finance |
| ICD | Interface Control Document | - | Business and Finance |
| ICDM | International Commission On Dynamic Meteorology | - | Business and Finance |
| ICE | Intercomparison Experiment | - | Business and Finance |
| ICE | Isoprene Closure Experiment | - | Business and Finance |
| ICE | Isoprene Canopy Experiment | - | Business and Finance |
| ICE | International Cirrus Experiment | - | Business and Finance |
| ICECOLORS | Cold Water Component Of WATERCOLORS | - | Business and Finance |
| ICES | International Council For The Exploration Of The Sea | - | Business and Finance |
| ICEX | Ice Experiment | - | Business and Finance |
| ICF | Instrument Control Facility | - | Business and Finance |
| ICFD | Institute For Computational Fluid Dynamics | - | Business and Finance |
| ICG | International Coordination Group | - | Business and Finance |
| ICH | Inter-Union Commission On The Lithosphere | - | Business and Finance |
| ICH | Inter-Union Commission On The Lithosphere | - | Business and Finance |
| ICITA | International Cooperative Investigation Of The Tropical Atlantic | - | Business and Finance |
| ICITA | International Cooperative Investigation Of The Tropical Atlantic | - | Business and Finance |
| ICJOB | IBM-to-Cray Interactive Interface | - | Business and Finance |
| ICMAP | CSMP | - | Business and Finance |
| ICMSSR | Interagency Committee For Meteorological Services And Supporting Research | - | Business and Finance |
| ICMUA | IAMAS Commission On The Meteorology Of The Upper Atmosphere | - | Business and Finance |
| ICN | International Communications Network | - | Business and Finance |
| ICO | Interagency Committee On Oceanography | - | Business and Finance |
| ICO | Initial Operating Capability | - | Business and Finance |
| ICPM | International Commission On Polar Meteorology | - | Business and Finance |
| ICS | Intercom System | - | Business and Finance |
| ICS | Interdisciplinary Climate Systems | - | Business and Finance |
| ICSI | International Commission On Snow And Ice | - | Business and Finance |
| ICSU | International Council Of Science | - | Business and Finance |
| ICWF | Interactive Computer Worded Forecast | - | Business and Finance |
| ICWG | International Coordinating Working Group | - | Business and Finance |
| ICWWP | Interagency Committee For World Weather Programs | - | Business and Finance |
| ID | Inside Diameter | - | Business and Finance |
| IDA | Institute For Defense Analysis | - | Business and Finance |
| IDASS | Integrated Data Assimilation/Sounding System | - | Business and Finance |
| IDB | Immediate Direct Broadcast | - | Business and Finance |
| IDCS | Image-dissector Camera System | - | Business and Finance |
| IDD | Internet Data Distribution | - | Business and Finance |
| IDD | Interface Definition Document | - | Business and Finance |
| IDEA LAB | Interactive's Digital Environmental Analysis Lab | - | Business and Finance |
| IDEAS | Instrumentation Development And Education In Airborne Science | - | Business and Finance |
| IDI | Instrumentation Development And Intercomparisons | - | Business and Finance |
| IDL | Interactive Display Language | - | Business and Finance |
| IDL | Interactive Data Language | - | Business and Finance |
| IDL | Interface Definition Language | - | Business and Finance |
| IDNDR | International Decade For Natural Disaster Reduction | - | Business and Finance |
| IDNHR | International Decade Of Natural Hazard Reduction | - | Business and Finance |
| IDOE | International Decade Of Ocean Exploration | - | Business and Finance |
| IDR | Incremental Design Review | - | Business and Finance |
| IDS | Interdisciplinary Study | - | Business and Finance |
| IDS | International Data Service | - | Business and Finance |
| IEA | International Energy Agency | - | Business and Finance |
| IEE | Institute Of Electrical Engineers | - | Business and Finance |
