United States Army Counterintelligence (ACI) is the component of United States Army Military Intelligence which conducts counterintelligence activities to detect, identify, assess, counter, exploit and/or neutralize adversarial, foreign intelligence services, international terrorist organizations, and insider threats to the United States Army and U.S. Department of Defense (DoD).

The mission of Army Counterintelligence (ACI) is to detect, Identify, Neutralize, and Exploit the Foreign Intelligence and International Terrorist threat against the U.S. Army Personnel, Facilities, Equipment, Information, Automations, and Equities. We best achieve this by providing tailored CI support to our supported organizations.

It is the mission of U.S. Army Counterintelligence (ACI) to detect, identify, counter, neutralize, and exploit hostile Foreign Intelligence Entities (FIE) and International Terrorist Organizations (ITO) targeting U.S. Army personnel and equities, as well as, additional joint equities as designated by the Department of Defense (DoD).

The Counter Intelligence Corps (Army CIC) was a World War II and early Cold War intelligence agency within the United States Army consisting of highly trained special agents. Its role was taken over by the U.S. Army Intelligence Corps in 1961 and, in 1967, by the United States Army Intelligence Agency.