ACM
- AC Milan
- AC Monza
- AECOM
- AGM-129 ACM
- Abstract Control Model
- Academy of Contemporary Music
- Academy of Country Music
- Adaptive coding and modulation
- Advanced case management
- African Content Movement
- Air chief marshal
- Air combat manoeuvring
- Air cycle machine
- Alcoholic cardiomyopathy
- Alkyl acrylate copolymer
- Allegany College of Maryland
- Alliance for Community Media
- Aluminium composite material
- American Center for Mobility
- American Ceylon Mission
- Anaconda Copper Mining Company
- Anti-Coalition Militia
- Anti-cult movement
- Antônio Carlos Magalhães
- Arica Airport (Colombia)
- Arrhythmogenic cardiomyopathy
- Asbestos
- Asian Civilisations Museum
- Associated Colleges of the Midwest
- Association for College Management
- Association for Computing Machinery
- Association for Contemporary Music
- Association of Children's Museums
- Asynchronous communication mechanism
- Attorney–client matching
- Audio Compression Manager
- Australasian Correctional Management
- Australian Community Media
- Australians for Constitutional Monarchy
- Automated charging machine
- Automobile Club de Monaco
- Barry Silesky
- Iraqi Arabic
- List of mine warfare vessels of the United States Navy
- Netherlands Authority for Consumers and Markets