Marines looking for career opportunities outside their regular military occupational specialty (MOS) can seek what's known as a B-billet. This is a chance for them to progress in their careers while getting valuable on-the-job experience.
A billet is not a standard Marine Corps job, and as such doesn't typically have a MOS associated with it. But many are classified under billet designators which serve as a placeholder for billets that fall outside the traditional job duties.
While a B-billet is a good way for a Marine to get some additional training, this doesn't mean that a Marine can dabble in a "side job" that is totally unrelated to his or her current role. For instance, an enlisted Marine in a legal administration MOS isn't likely to be able to get a B-billet in an infantry role. It's not a way for a Marine to get out of his or her current job, either, as they'll still have obligations to the Corps that must be fulfilled.
Marine Corps Billet Designator Overview
A billet was originally a term for a soldier's sleeping quarters and used to mean a private home which was required to let the soldier sleep there. When they aren't on combat duty, most military personnel are billeted in barracks or garrisons, unless they have a family home near their post.
The term has evolved to mean a particular job assignment, usually within the U.S. Navy, U.S. Marine Corps or U.S. Coast Guard, which may be filled by a single person. It's outside the military's MOS systems, but a B-billet is a job that has become part of the Marine Corps' responsibilities.
Here are the four B-billets in the Marine Corps:
Marines can choose from four different B-billets which each carry a three-year tour of duty. One of the most popular B-billets is that of the drill instructor. This is the quintessential Marine, the iconic, tough-as-nails instructor for new recruits. Enlisted Marines ranked sergeant or above are eligible for this B-billet
A recruiter is another B-billet that is very popular among enlisted Marines. These are the front lines in the effort to enlist more people in the Marine Corps, so the hours are long, and the work can be challenging. It may involve speaking before a group or talking to strangers about the benefits of joining the Marines. This is a job suited for someone with an outgoing personality who has the power of persuasion.
Marines Security Force
Another B-billet option for Marines is serving in the Marine Security Force. These are the Marines you'll see giving a security escort to high-profile government figures like the president or vice-president. This may present opportunities to travel and guard ambassadors and American embassies in other countries.
Marine Combat Training Instructor
And finally, the B-billet that lets a Marine get back to his or her boot camp days, but on the other end of the training. Marine combat training instructors teach new recruits the survival and combat skills they'll need to survive.