MCI

MCI may refer to:

• mCi, millicurie, 1/1000 of a curie, a non-SI unit of radioactivity
• MCi, megacurie, 1,000,000 times a curie, a non-SI unit of radioactivity, 1 MCi = 3.7×10¹⁶ decays per second or becquerels
• 1101 in Roman numerals

Companies

• MCI Group, the world's largest professional conference organizer
• MCI Inc., a former American telecommunications company acquired by Verizon Communications
• MCI Communications, originally Microwave Communications Inc., the corporation that operated as MCI from 1963 to 1998
• Mobile Telecommunication Company of Iran
• Motor Coach Industries, a coach/bus manufacturing company
• Music Center Incorporated, later known as Music Consultants Incorporated, a company that manufactured multi-track audiotape recorders and mixing consoles for professional studio recording

Education

• Maine Central Institute, a boarding school in Maine, founded in 1866
• Marine Corps Institute, a coursework of Marine Corps education and training programs
• Martingrove Collegiate Institute, a secondary school located in Toronto, Ontario
• Mennonite Collegiate Institute, a private, religious school in the town of Gretna, in Southern Manitoba
• Museum Conservation Institute, of the Smithsonian Institution

Health and science

• Medical Council of India, India's medical education controlling body
• Magnetic current imaging, using a scanning SQUID microscope
• Mass casualty incident, a medical emergency involving more patients than can be easily handled by the crews initially assigned to the incident
• Mild cognitive impairment, a neurological affliction often associated with Alzheimer's disease
• Modulation contrast imaging, a term related to optical imaging
• Muconate lactonizing enzyme, an enzyme
• Macroinvertebrate Community Index, an index where the presence or lack of macroinvertebrates is used for monitoring stream health in New Zealand.

Organizations

• Medical Council of India
• Motek Cultural Initiative, a Toronto-based nonprofit organization promoting Israeli music and culture

Other

• Malicious caller identification, a type of enhanced telephone service
• MCI Management Center Innsbruck, a university located in Innsbruck, Austria
• MCI, the IATA airport code for the Kansas City International Airport in Kansas City, Missouri
• MCI, MCI Records, Frank Farian's record label
• Meal, Combat, Individual ration, the successor to the US Army C-ration
• Media Control Interface, an API for controlling multimedia peripherals connected to a Microsoft Windows or OS/2 computer
• Michigan City (Amtrak station), Indiana; Amtrak station code MCI
• Miss Chinese International Pageant, an annual pageant for international women of Chinese descent
• Monetary conditions index, a macroeconomic index number relevant for monetary policy