Aviation

• Minimum crossing altitude, a minimum obstacle crossing altitude for fixes on published airways

Chemistry

• Monochloroacetic Acid, carboxylic acid, manufactured by chlorinating acetic acid
• Metabolic Control Analysis, method for analysing how the control of fluxes and intermediate concentrations in a metabolic pathway is distributed among the different pathway enzymes

Companies

• MCA Inc., a now defunct company (originally called Music Corporation of America) and its subsidiary companies:
• MCA Records
• MCA Nashville Records
• MCA Home Video, former name of Universal Studios Home Entertainment

Culture

• A Museum of Contemporary Art
• Maine Center for the Arts
• Museum of Contemporary Art, Sydney
• Adam Yauch, aka "MCA" of the Beastie Boys
• Morangos com Açúcar, a Portuguese youth telenovela (2003-present)

Education

• Master of Computer Applications, a three-year Professional Master's degree in Computer Science awarded in India
• Maranatha Christian Academy, a Marikina (Philippines)-based Christian school, now called as the National Christian Life College
• Memphis College of Art, an art school in Tennessee
• Microsoft Certified Architect, a certification available from Microsoft
• Middlesex County Academy, a high school in New Jersey

Law

• The Military Commissions Act of 2006

Medicine

• Middle cerebral artery, one of the three major blood supplies to the brain
• Motorcar accident

Organisations

• Malaysian Chinese Association, a political party in Malaysia
• Maritime and Coastguard Agency, an agency of the United Kingdom Government.
• Medicines Control Agency, which joined with the Medical Devices Agency to become the Medicines and Healthcare products Regulatory Agency
• Millennium Challenge Account, a U.S. program for aid to developing countries
• MultiCultural Aotearoa, a New Zealand political action group
• Mumbai Cricket Association, ruling body for cricket in Mumbai
• Mustang Club of America, MCA is a non-profit organization dedicated to the preservation, care, history and enjoyment of all model years of Ford Mustang, Shelby, Boss, Saleen, Roush, SVT Cobra, Steeda and McLaren.
• Morrison Academy, a Christian international school in Taichung, Taiwan.

Sports

• Margaret Court Arena
• MC Algiers

Technologies

• Machine check architecture
• Machine Check Abort Error Recovery, HP-UX feature for recovering from Machine Check Aborts (MCAs)
• Micro Channel architecture, a type of computer bus
• Medium Combat Aircraft, a 5th generation fighter aircraft being designed by India.
• Marine Cranking Amps measurement of a Car battery
• Maximum credible accident, a concept used in risk management
• Master of Computer Applications, Three year post graduate course Post Graduate Studies
• Multichannel Analyzer, a detection instrument that can measure on several channels, to enable spectral analysis
• The Multicore Association, an industry group focusing on multitasking APIs, communication APIs, and debugging in multicore processors.