marine corps time in grade requirements
Selection for commander -- the O-4 officer pay grade equivalent to a major in the Army, Air Force or Marine Corps -- requires that the candidate for promotion must have served three years as a lieutenant to meet the required time-in-grade.A lieutenant must also have between nine and 11 years of military service.ommander. Reaching the rank of commander, O-5, from the rank of lieutenant commander requires an officer to have served a total of three years as a lieutenant commander to meet the time-in-grade requirement. The officer must also have between 15 and 17 years of total military service.