Brigadier general ( United States ) A brigadier general in the United States Army , Air Force , and Marine Corps , is a one - star general officer , with the pay grade of O - 7 . Brigadier general ranks above a colonel and below major general . Brigadier general is equivalent to the rank of rear admiral ( lower half ) in the other uniformed services . Statutory limits . U . S . Code of law explicitly limits the total number of general officers that may be on active duty . The total of active duty general officers is capped at 302 for the Army , 279 for the Air Force , and 80 for the Marine Corps . Some of these slots are reserved by statute . Promotion , appointment and tour length . For promotion to the permanent grade of brigadier general , eligible officers are screened by a promotion board consisting of general officers from their branch of service . This promotion board then generates a list of officers it recommends for promotion to general rank . This list is then sent to the service secretary and the joint chiefs for review before it can be sent to the President , through the defense secretary , for consideration . The President nominates officers to be promoted from this list with the advice of the Secretary of Defense , the service secretary , and if applicable , the service ' s chief of staff or commandant . The President may nominate any eligible officer who is not on the recommended list if it serves in the interest of the nation , but this is extremely rare . , 10 USC 5149 . Office of the Judge Advocate General : Deputy Judge Advocate General ; Assistant Judge Advocates General must then confirm the nominee by a majority vote before the officer can be promoted . Once a nominee is confirmed , they are promoted to that rank once they assume a position of office that requires an officer of that rank . For positions of office reserved by statute , the President nominates an officer for appointment to fill that position . For all three uniformed services , because the grade of brigadier general is a permanent rank , the nominee may still be screened by an in - service promotion board . Since the grade of brigadier general is permanent , the rank does not expire when the officer vacates a one - star position . Tour length varies depending on the position , by statute , and / or when the officer receives a new assignment but the average tour length per one - star billet is two to four years . Retirement . Other than voluntary retirement , statute sets a number of mandates for retirement . All brigadier generals must retire after five years in grade or 30 years of service , whichever is later , unless selected or 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 general 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 . History . The rank of Brigadier General has existed in the United States armed forces since the American Revolutionary War . A brigadier general was , at first , strictly an infantry officer who commanded a brigade ; however , over the course of the 19th and 20th centuries , the responsibilities of the rank expanded significantly . During the period from March 16 , 1802 to January 11 , 1812 , the rank of Major General was abolished and Brigadier General became the highest rank in the U . S . Army . Foreseeing the need for an expanded general staff in case of war , which seemed imminent , Congress restored the rank of Major General in January 1812 . The first Brigadier General in the U . S . Marine Corps was Commandant Archibald Henderson , promoted to the rank of brevet Brigadier General in the 1830s for his service in the Second Seminole War . The first non - brevet Brigadier General in the Marines was Commandant Jacob Zeilin who was promoted to the rank in 1874 , but when he retired in 1876 , Colonel once again became the highest rank in the Marines until March 1899 when Commandant Charles Heywood was promoted . Ever since then the office of Commandant has been held by a general officer , with the permanent rank of the Commandant raised to Major General in 1908 and to first Lieutenant General and then General during World War II , which rank it has held ever since . The insignia for a brigadier general is one silver star worn on the shoulder or collar , and has not changed since the creation of the rank two centuries ago . Since the Mexican - American War , however , the lower rank of colonel has been the normal rank appointed to command a brigade . Today , an Army or Marine Corps " BG " typically serves as Deputy Commander to the Commanding General of a division or division - sized units and assists in overseeing the planning and coordination of a mission . In an infantry brigade not attached to a division , a Brigadier General serves as the unit ' s commander , while a Colonel serves as deputy commander . An Air Force brigadier general typically commands a large wing . Additionally , one - star officers of all services may serve as high - level staff officers in large military organizations .