What is the rank designation for a Major General?

The rank designation for a Major General is O-8. In the U.S. military ranking system, officers are categorized by an "O" prefix followed by a corresponding numerical value based on their rank. The ranks progress as follows: O-1 is a Second Lieutenant, O-2 is a First Lieutenant, O-3 is a Captain, O-4 is a Major, O-5 is a Lieutenant Colonel, O-6 is a Colonel, O-7 is a Brigadier General, O-8 is a Major General, O-9 is a Lieutenant General, and O-10 is a General. Since a Major General is next in rank above a Brigadier General and directly below a Lieutenant General, its designation is appropriately O-8. This hierarchical structure is crucial in defining the roles and authority within the military, guiding promotions, and ensuring an organized command system.