The United States Code explicitly limits the total number of generals that may be concurrently active to 231 for the Army, 62 for the Marine Corps, and 198 for the Air Force.

Lieutenant generals must retire after 38 years of service unless appointed for promotion or reappointed to grade to serve longer.

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.

[6] Historically, officers leaving three-star positions were allowed to revert to their permanent two-star ranks to mark time in lesser jobs until statutory retirement, but now such officers are expected to retire immediately to avoid obstructing the promotion flow.

During the Quasi War with France, President John Adams promoted George Washington to lieutenant general to celebrate his service in the American Revolution.

The rank of lieutenant general would not be awarded to an active American military commander until Ulysses S. Grant was promoted sixty years later, shortly before the end of the American Civil War, to recognize his position as overall commander of Union forces in the East.

[10] On February 28, 1855, President Franklin Pierce nominated Winfield Scott to be breveted lieutenant general, effective March 29, 1847, as an honor for his capture Veracruz and San Juan de Ulúa, during the Mexican–American War.

Additionally, lieutenant generals of all services serve as high-level staff officers at various major command headquarters and The Pentagon, often as the heads of their departments.