What is a first lieutenant?

A First Lieutenant is a commissioned officer rank in the military, typically found in the Army, Air Force, and Marine Corps. It is one rank above Second Lieutenant and below Captain. First Lieutenants often serve as platoon leaders, executive officers, or in various staff positions, where they are responsible for leading and managing groups of enlisted personnel and junior officers. They play a crucial role in planning missions, training troops, and ensuring the effective implementation of orders from higher command. Promotion to First Lieutenant usually occurs after 18 to 24 months of service as a Second Lieutenant.