What is the position title at O-4 level in the Marine Corps?

The position title at the O-4 level in the Marine Corps is Lieutenant Colonel. This rank signifies a officer who typically commands a battalion or serves in higher staff positions, reflecting significant operational experience and leadership. Officers at the O-4 level have usually completed substantial time in service and have demonstrated proficiency in their roles, having advanced through the ranks.

The other ranks mentioned hold different O-level classifications or enlisted ranks. Major, for instance, corresponds to the O-4 level but is that rank below Lieutenant Colonel. Captain is an O-3 rank, representing a lower level of command and responsibility. Lastly, Sergeant Major is an E-9 rank, which is the highest enlisted rank in the Marine Corps, distinct from officer ranks entirely. Each of these positions plays a significant role within the structure of the Marine Corps, but only Lieutenant Colonel pertains to the O-4 level.