In the United States Army

United States Army

The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

, United States Marine Corps

United States Marine Corps

The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...

, and United States Air Force

United States Air Force

The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

, major general is a two-star general-officer rank, with the pay grade of O-8. Major general ranks above brigadier general

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 in the other uniformed...

 and below lieutenant general

Lieutenant General (United States)

In the United States Army, the United States Air Force and the United States Marine Corps, lieutenant general is a three-star general officer rank, with the pay grade of O-9. Lieutenant general ranks above major general and below general...

. Major general is equivalent to the rank of rear admiral in the other uniformed services

Uniformed services of the United States

The United States has seven federal uniformed services that commission officers as defined by Title 10, and subsequently structured and organized by Title 10, Title 14, Title 33 and Title 42 of the United States Code.-Uniformed services:...

, and is the highest permanent rank during peacetime in the uniformed services. (The higher ranks are temporary ranks linked to specific positions, although virtually all officers who have been promoted to those ranks are approved to retire at their highest earned rank.)
The United States Code

United States Code

The Code of Laws of the United States of America is a compilation and codification of the general and permanent federal laws of the United States...

 explicitly limits the total number of general officers that may be on active duty at any given time.