In the U.S. Army and the U.S. Marine Corps, a second lieutenant typically leads a platoon-size element (16 to 44 soldiers or marines). In the Army, the rank bore no insignia until December 1917, when a gold bar was introduced to contrast with the silver bar of a first lieutenant.
In the U.S. Air Force, a second lieutenant may supervise flights of varying sizes, depending upon the career field, as a flight commander or assistant flight commander or may work in a variety of administrative positions at the squadron, group, or wing level.
In the Army Medical Corps, this is the entry-level rank for nurses.
|United States warrant officer ranks|
|Approximate insignia:||(no universal insignia)||(no universal insignia)||(no universal insignia)||(no universal insignia)||(no universal insignia)|
|United States Air Force:||WO-1||CWO-2||CWO-3||CWO-4||CWO-5|
|United States Army:||WO1||CW2||CW3||CW4||CW5|
|United States Marine Corps:||WO-1||CWO-2||CWO-3||CWO-4||CWO-5|
|United States Navy:||WO-1||CWO-2||CWO-3||CWO-4||CWO-5|
|United States Coast Guard:||||CWO-2||CWO-3||CWO-4|||
|United States Public Health Service:|||||||||||
|Nat'l Oceanic & Atmospheric Administration:|||||||||||
Grade is authorized for use by U.S. Code but has not been created