Major (United States)
- Please see "Major" for other countries that use this rank
In the United States Army, Air Force, and Marine Corps, major is a field grade military officer rank just above the rank of captain and just below the rank of lieutenant colonel. It is equivalent to the naval rank of lieutenant commander in the other uniformed services, although lieutenant commanders are considered junior officers by their respective services while the rank of major is considered field grade.
The pay grade for the rank of major is O-4. The insignia for the rank consists of a golden oak leaf, with slight stylized differences between the Army/Air Force version and the Marine Corps version. Promotion to major is governed by Department of Defense policies derived from the Defense Officer Personnel Management Act of 1980. DOPMA guidelines suggest 80% of captains should be promoted to major after serving a minimum of three years at their present rank and after attaining nine to eleven years of cumulative commissioned service.
A major in the U.S. Army typically serves as a battalion executive officer (XO) or as the battalion operations officer (S3). A major can also serve as a primary staff officer for a regiment, brigade or task force in the areas concerning personnel, logistical and operations. A major will also be a staff officer / action officer on higher staffs and headquarters. In addition, majors command augmented companies in Combat Service and Service Support units. U.S. Army majors also command Special Operations companies, such as U.S. Army Special Forces companies, Civil Affairs companies, Military Information Support Operations companies, some Aviation companies, as well as certain types of separate, numbered vice lettered, Military Intelligence companies.
Virtually all majors in the United States Army attend the 10-month Command and General Staff School at Fort Leavenworth, with a smaller number attending satellite schools administered by Fort Leavenworth at Fort Belvoir, Fort Lee, Virginia and Fort Gordon. Nine-hundred-sixty graduated from the Leavenworth course in 2009 (the largest class in Army history).
American Civil War 
During the American Civil War the Union Army continued to use the existing titles of rank and rank insignia established for the US Army. After the Southern states seceded and became the Confederate States of America, the Confederate Army retained the same titles of rank as its Union counterpart, but developed a new system of rank identification and insignia for its officers.
While Union officers continued to wear their rank insignia on their shoulder straps, Confederate officers wore their rank insignia on the collar (one, two, or three horizontal gold bars for lieutenants and captains; one, two, or three gold stars for field grade officers; and three gold stars surrounded by a wreath for all general officers), as well as rows of gold lace forming an Austrian knot pattern on each sleeve. The number of rows of gold lace increased with the rank of the officer.
Air Force 
A major in the Air Force typically has duties as a senior staff officer at the squadron and wing level. In flying squadrons majors are generally flight commanders or assistant directors of operations. In the mission support and maintenance groups majors may occasionally be squadron commanders. In the medical corps, a major may be the head of a clinic or flight.
- "College - Command and General Staff College Foundation". Cgscfoundation.org. Retrieved 2010-03-16.
- "Largest CGSC-ILEâ€ˆclass graduates". Army.mil. Retrieved 2010-03-16.
|United States commissioned officer and officer candidate ranks|
|Pay grade / Branch of service||Officer
|Air Force||Cadet / OT||2d Lt||1st Lt||Capt||Maj||Lt Col||Col||Brig Gen||Maj Gen||Lt Gen||Gen||GAF|||
|Army||CDT / OC||2LT||1LT||CPT||MAJ||LTC||COL||BG||MG||LTG||GEN||GA||GAS|
|Marine Corps||Midn / Cand||2ndLt||1stLt||Capt||Maj||LtCol||Col||BGen||MajGen||LtGen||Gen|||||
|Navy||MIDN / OC||ENS||LTJG||LT||LCDR||CDR||CAPT||RDML||RADM||VADM||ADM||FADM||AN|
|Coast Guard||CDT / OC||ENS||LTJG||LT||LCDR||CDR||CAPT||RDML||RADM||VADM||ADM|||||
|Public Health Service||||ENS||LTJG||LT||LCDR||CDR||CAPT||RADM||RADM||VADM||ADM|||||
|National Oceanic and
 Proposed General of Armies insignia; John J. Pershing was given as the insignia for the rank
 Grade is inactive; requires Congressional approval for re-activation
 Grade is authorized by the U.S. Code for use but has not been created
 Grade has never been created or authorized
|United States warrant officer ranks|
|Public Health Service|||||||||||
|National Oceanic and
 Grade is authorized for use by U.S. Code but has not been created
 Grade never created or authorized