Lieutenant (United States)

The military rank of lieutenant is the commissioned officer rank title associated with pay grades O-3 and O-2 in the United States Armed Forces military branches of the United States Navy and the United States Coast Guard.

It is also used in the commissioned officer ranks of the United States Uniformed Services of the National Oceanic and Atmospheric Administration with their National Oceanic and Atmospheric Administration Commissioned Officer Corps (NOAA-COO), and the medical arm of the United States Public Health Service with their United States Public Health Service Commissioned Corps (PHS-CC).

The rank of lieutenant is divided between the following:

Lieutenant (pay grade O-3), abbreviated as LT and equivalent to a Captain in the U.S. Army, U.S. Marine Corps, U.S. Air Force and U.S. Space Force

Lieutenant, junior grade (pay grade O-2), abbreviated as LTJG and sometimes referred as "lieutenant j.g." It is equivalent to the rank of First Lieutenant (O-2), sometimes called simply "lieutenant," in the United States Army, Marine Corps, Air Force, and Space Force.

Neither of the above naval style ranks should be confused with the rank of Second Lieutenant (pay grade O-1), in the U.S. Army, Air Force, Marine Corps and Space Force, which is equivalent to the rank of Ensign in the Navy, Coast Guard, NOAA-COO & PHS-CC.

During the American Civil War (1861–1865), brevet second lieutenants in the federal Union Army and southern Confederate States Army were sometimes also known as "third lieutenants".

Civilian police and fire departments in the United States may also use the rank of lieutenant.