The main difference between primary and collateral duty Command Master Chiefs is that a primary duty Command Master Chief is permanently assigned to a command by the Bureau of Naval Personnel.?

The main difference between primary and collateral duty Command Master Chiefs lies in their assignment status and responsibilities. A primary duty Command Master Chief is permanently assigned to a command and plays a central role in leadership and operational effectiveness. In contrast, a collateral duty Command Master Chief typically has additional responsibilities alongside their primary role and may not be permanently assigned to that specific command. This distinction affects the level of commitment and focus each type of Command Master Chief can dedicate to their duties.