Organizations and institutes

• IMS Global, a non-profit standards organization concerned with establishing interoperability for learning systems and learning content
• Indian Medical Service, a military medical service in British India
• Insight Meditation Society, a Buddhist organization located in Barre, Massachusetts
• Institute of Mathematical Statistics, an international professional and scholarly society
• International Magicians Society, the world's largest professional association for magicians
• Irish Marching Society, a group of individuals in the city of Rockford, Illinois who wanted to come together to celebrate the Irish Heritage
• Irish Mathematical Society, the main professional organization for mathematicians in Ireland

Schools

• Institute of Medical Sciences, Banaras Hindu University, one of the three institutes of Banaras Hindu University in Varanasi, India
• Iowa Mennonite School, a private Christian high school near Kalona, Iowa

Businesses and companies

• IMS Associates, Inc., an early computer manufacturer
• IMS Bildbyrå, a Swedish stock photograph agency acquired by Nordicphotos
• IMS Health, an international consulting and data services company that supplies the pharmaceutical industry
• Integrated Micro Solutions, a manufacturer of graphics processing units

Science, medicine and technology

• Industrial methylated spirit, ethanol that has been rendered toxic or otherwise undrinkable
• Insulated metal substrate, a substrate used in power electronics applications
• Intelligent Munitions System, American smart mine
• Intravenous Marijuana Syndrome, the clinical name for symptoms occurring after IV injection of boiled cannabis
• Immunomagnetic separation, a laboratory test
• Ion mobility spectrometer, a highly sensitive analytical instrument
• Irritable Male Syndrome, a term for a set of symptoms thought to be caused by a drop in testosterone levels in male mammals

Computers and Internet

• Information Management System, a combination database management system and transaction processing system from IBM
• Internet Map Server, a server that provides maps through the Internet
• Internet Medieval Sourcebook, a web archive with Medieval source documents
• IMTEK Mathematica Supplement, open source Mathematica packages and tutorials
• IP Multimedia Subsystem, a set of specifications from 3GPP for delivering IP multimedia to mobile users

Other

• Indianapolis Motor Speedway, located in Speedway, Indiana
• Integrated master schedule, a time-based expansion of the integrated master plan
• International Measurement System, a handicapping system used in sailboat racing