Lieutenant colonel (United States)

In the United States Army, Marine Corps, Air Force and Space Force, lieutenant colonel is a field grade officer rank, just above the rank of major and just below the rank of colonel. It is equivalent to the naval rank of commander in the other uniformed services.

The pay grade for the rank of lieutenant colonel is O-5. In the United States armed forces, the insignia for the rank is a silver oak leaf, with slight stylized differences between the version of the Army and the Air Force and that of the Navy and the Marine Corps. Oak leaves and acorns were used in the early American army on high ranking officer's headwear and may have come from the British or Germans as oak leafs and acorns were used in German uniforms in the 18th Century. The Army and US Air Force oak leaf is a stylized silver leaf that does not represent any individual tree. The Marine Corps version is styled like a navy Commander's and is similar to a southern live oak leaf grown in the Naval Live Oaks Reservation in the 19th Century.

Promotion to lieutenant colonel is governed by Department of Defense policies derived from the Defense Officer Personnel Management Act (DOPMA) of 1980, for officers in the Active Component, and its companion Reserve Officer Personnel Management Act (ROPMA), for officers in the Reserve Component (e.g., Reserve and National Guard). DOPMA guidelines suggest that 70 percent of majors be promoted to lieutenant colonel after serving at least three years at their present rank and after 15–17 years of cumulative commissioned service.