As of 2025, the United States Department of Defense operated 11 unified combatant command, also referred to as a combatant command (CCMD). These are joint military commands composed of units from two or more service branches, and conduct continuing missions. Each CCMD is the highest echelon of military commands, in order to optimize command and control of all forces, regardless of branch of service, during peace or war. CCMDs are organized either on a geographical basis (known as an "area of responsibility", AOR) or on a functional basis, e.g., special operations, force projection, transport, and cybersecurity. Currently, seven CCMDs are geographical, and four are functional. CCMDs have specific badges denoting their affiliation.
The Unified Command Plan (UCP) establishes the missions, command responsibilities, and geographic areas of responsibility of the CCMDs. Each time the UCP is updated, the organizations are reviewed for efficiency, efficacy, and alignment with national policy.