In the United States Army, U.S. Marine Corps, U.S. Air Force and U.S. Space 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 (Navy and Coast Guard), the rank of major is that of a senior officer in the United States Army, the United States Marine Corps, and the United States Air Force.