In the United States Army, Marine Corps, and Air Force, major is a field grade military officer rank above the rank of captain and below the rank of lieutenant colonel. It is equivalent to the naval rank of lieutenant commander in the other uniformed services. Although lieutenant commanders are considered junior officers by their respective services, the rank of major is considered field grade in the United States Army and the United States Marine Corps.
The pay grade for the rank of major is O-4. The insignia for the rank consists of a golden oak leaf, with slight stylized differences between the Army/Air Force version and the Marine Corps version. Promotion to major is governed by Department of Defense policies derived from the Defense Officer Personnel Management Act of 1980.
A major in the U.S. Army typically serves as a battalion executive officer (XO) or as the battalion operations officer (S3). A major can also serve as a primary staff officer for a regiment, brigade or task force in the areas concerning personnel, logistics, intelligence, and operations. A major will also be a staff officer / action officer on higher staffs and headquarters. In addition, majors command augmented companies in Combat Service and Service Support units. U.S. Army majors also command Special operations companies, such as U.S. Army Special Forces companies, Civil Affairs companies, Military Information Support Operations companies, as well as certain types of separate, numbered vice lettered, Military Intelligence companies.