Lieutenant general (United States)
In the United States Armed Forces, a lieutenant general is a three-star general officer in the United States Army, Marine Corps, Air Force, and Space Force. A lieutenant general ranks above a major general and below a general. The pay grade of lieutenant general is O-9. It is equivalent to the rank of vice admiral in the other United States uniformed services which use naval ranks. It is abbreviated as LTG in the Army, LtGen in the Marine Corps, and Lt Gen in the Air Force and Space Force. Statutory limits. The United States Code  explicitly limits the total number of generals that may be concurrently active to 231 for the Army, 62 for the Marine Corps, and 198 for the Air Force. For the Army and Air Force, no more than about 25% of the service's active duty general officers may have more than two stars. Some of these slots can be reserved by statute. Officers serving in certain intelligence positions are not counted against either limit, including the Deputy Director of the Central Intelligence Agency. The President may also add three-star slots to one service if they are offset by removing  an equivalent number from other services. Finally, all statutory limits may be waived at the president's discretion during time of war or national emergency. Appointment and tour length. The three-star grade goes hand-in-hand with the position of office to which it is linked, so the rank is temporary. Officers may only achieve three-star grade if they are appointed to positions that require the officer to hold such a rank. Their rank expires with the expiration of their term of office, which is usually set by statute. Lieutenant generals are nominated for appointment by the president  from any eligible officers holding the rank of brigadier general or above, who also meet the requirements for the position, with the advice of the Secretary of Defense and the Chairman of the Joint Chiefs of Staff. The nominee must be confirmed via majority vote by the Senate before the appointee can take office and thus assume the rank. The standard tour length for most lieutenant general positions is three years but some are set four or more years by statute. Extensions of the standard tour length can be approved, within statutory limits, by their respective service secretaries, the Secretary  of Defense, the president, or Congress but these are rare, as they block other officers from being promoted. Some statutory limits under the U.S. Code can be waived in times of national emergency or war. Three-star ranks may also be given by an act of Congress but this is extremely rare. Retirement. Other than voluntary retirement, the statute sets a number of mandates for retirement. Lieutenant generals must retire after 38 years of service unless appointed for promotion or reappointed to grade to serve longer. Otherwise, all general officers must retire the month after their 64th birthday. However, the  Secretary of Defense can defer a three-star officer's retirement until the officer's 66th birthday and the president can defer it until the officer's 68th birthday. General officers typically retire well in advance of the statutory age and service limits, so as not to impede the upward career mobility of their juniors. Since there is a finite number of three-star slots available to each service, typically one officer must leave office before another can be promoted. Maintaining a three-star rank is a game of musical chairs; once an officer vacates a position bearing that rank , they have 60 days to be appointed or reappointed to a position of equal or higher importance or involuntarily retire. Historically, officers leaving three-star positions were allowed to revert to their permanent two-star ranks to mark time in lesser jobs until statutory retirement, but now such officers are expected to retire immediately to avoid obstructing the promotion flow. Modern use. An Army or Marine Corps lieutenant general typically commands a corps-sized unit (20,000 to 45,000 soldiers for an Army Corps and a similar number of Marines for a Marine Expeditionary Force), while an Air Force lieutenant general  commands a large Numbered Air Force consisting of several wings or a smaller USAF Major Command (MAJCOM) such as the Air Force Special Operations Command or the Air Force Reserve Command. 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. In 2014 five women were serving as lieutenant generals in the US Army. After the close of the Second World War, generals were normally promoted permanently to brigadier general and major general, with temporary promotions to lieutenant general and general to fill  senior positions as needed. In theory, a general vacates their three or four-star rank at the termination of their assignment unless placed in an equal ranking billet. Douglas MacArthur, who served as a 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 general and general grades as a temporary rank continues, with the President and the Department of Defense creating temporary or indefinite three- and four-star assignments, with a fixed term of office , with the approval of the Senate. Even with the temporary status, such officers are also almost always granted permanent retirement in the last grade they held with the satisfactory completion of at least two or three years in grade. Famous lieutenant generals. Historic. Listed in order of receiving the rank: