In the United States Marine Corps Lieutenant General is a three-star general officer, with the pay grade of O-9. Lieutenant General ranks above
Major General and below
General. Lieutenant General is equivalent to a vice admiral in the other uniformed services.
Lieutenant General - An Army or Marine Corps Lieutenant General typically commands a corps-sized unit (20,000 to 45,000 soldiers), while an Air Force Lieutenant General commands a large Numbered Air Force consisting of several wings. Additionally, Lieutenant Generals of all services serve as high-level staff officers at various major command headquarters and The Pentagon, often as the heads of their departments.
After the close of the Second World War, Generals were normally promoted permanently to Brigadier General and Major General, with temporary promotions to Lieutenant and full General to fill senior positions as needed. In theory, a General would be expected to vacate their three- or four-star rank at the termination of their assignment, unless they were placed in an equal ranking billet. Douglas MacArthur, who served as four-star general and Army Chief of Staff, reverted to two stars after his CoS tour ended but chose to stay on active duty in the United States Army.
The practice of using Lieutenant and full General as a temporary rank continues to the current day, although the term “temporary” is in name only since most three- and four-star generals are expected to retain their rank regardless of their assignment. Such officers are also almost always granted permanent retirement rank, as well, in the last grade they held.
