Imbaimadai - Guyana - Airport symbol (OAG)
Imbel - NCIC firearms make code (NCIC)
Independent Mixed Brigade - Military
Independent Mortar Battery - British military (DMA)
Indian Mountain Battery - British military (DMA)
Industrial Multimedia Branch - Environmental Protection Agency (RCD)
Information Management Branch (AUEG)
Ingenieurtechnologien fur Materialprufung und Bauwerkserhaltung GmbH (EFIS)
Input Memory Buffer - Computer science
Institute for Marine Biochemistry - British
Institute for Marine Biosciences - Research center (RCD)
Institute of Marine Biology (SAUO)
Institute of Microbiology
Institute of Molecular Biophysics - Florida State University - Research center (RCD)
Institute of Molecular Biotechnology - Germany
Instrument Material Bulletin (MCD)
Integration Management Board (ACAE)
Intel Media Bench (SAUS)
Interaction of Man and the Biosphere (SAUS)
InterCapital Ins Muni Bd Fd - NYSE symbol
InterCapital Insurance Municipal Bond Fund - NYSE symbol (SPSG)
Intercontinental Medical Book Corp.
Intermenstrual Bleeding - Medicine
Intermode Bus (SAUS)
Inter-Module Bus (NITA)
Intermountain Tariff Bureau Inc. (SAUO)
Intermountain Tariff Bureau, Inc., Salt Lake City UT - STAC
Internationaler Metalarbeiterbund - International Metalworkers' Federation
International Maritime Bureau - Research center - British (IRC)
International Mission Board (EA)
Investigator of Micro-Biosphere (EOSA)
Irish Meat Board (SAUO)
Irish Medicines Board (GVA)
Irvine/Michigan/Brookhaven - Experiment on proton decay
Kimberly, OR - Location identifier - FAA (FAAL)
Mahi Boats Inc., Chalmette, LA - Manufacturer code for watercraft hull identification number (USCG)