Lieutenant general ( United States ) In the United States Army , the United States Marine Corps and the United States Air Force , lieutenant general ( abbreviated as Lt Gen in the Air Force , LtGen in the Marine Corps and as LTG in the Army ) is a three - star general officer rank , with the pay grade of O - 9 . Lieutenant general ranks above major general and below general . Lieutenant general is equivalent to the rank of vice admiral in the other uniformed services . Statutory limits . The United States Code explicitly limits the total number of generals that may be concurrently active to 302 for the Army , 279 for the Air Force , and 80 for the Marine Corps . For the Army and Air Force , no more than 16 . 3 % of the service ' s active duty general officers may have more than two stars . Some of these slots are reserved by statute . For example , the Army and the Air Force , the Surgeon General and the Judge Advocate General for both branches are lieutenant generals . 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 , under the advice and / or suggestion of their respective department secretary , service secretary , and if applicable the joint chiefs . 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 are three years but some are set four or more years by statute . Note : Extensions of the standard tour length can be approved , within statutory limits , by their respective service secretaries , the Secretary of Defense , the President , and / 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 act of Congress but this is extremely rare . Retirement . Other than voluntary retirement , 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 ) , 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 general and general to fill senior positions as needed . In theory , a general vacates their three or four - star rank at termination of their assignment unless 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 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 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 :