Drill instructors supervise and instruct or assist in commanding and instructing a recruit platoon. Once voided, this MOS may not be reassigned without prior approval from the CMC (MM).

The Marine combat instructor instructs and assists in the training of basic combat skills to entry level Marines to include: weapons handling, automatic weapons, munitions, combat conditioning, land navigation, communications, NBC protection, offensive/defensive tactics and scouting/patrolling. The Marine combat instructor reinforces core values
instilled in recruit training by setting the superior example with professional conduct, knowledge, bearing and attitude, provides student performance counseling, assists in the conduct of parades and ceremonies, and maintains records and prepares reports.

Martial arts instructors conduct training in principles of close combat and core values.

Martial Arts instructor-trainers train and certify martial arts instructors. Additionally, they provide instruction to all personnel in hand-held weapons, unarmed against hand-held weapons, weapons of opportunity, ground fighting, firearm disarmament, and principles of core values.

Water Safety/Survival Instructors supervise and conduct water safety and survival programs and instruct personnel in the techniques and methodology of water safety and survival.

Marksmanship Instructors instruct in all phases of the Marine Corps Marksmanship Program on the qualification and requalification on small arms ranges. Additionally, they assist in the operation of firing ranges. This MOS may be assigned to a Marine or used as a billet designator.

Small arms weapons instructor conducts all phases of the Marine Corps Marksmanship training. They develop comprehensive marksmanship training plan based on commander's guidance. They conduct and supervise all small arms marksmanship-training evolutions in support of unit mission. This MOS may be assigned to a Marine or used as a billet designator.

Marksmanship coaches analyze difficulties of shooters during dry and live fire exercises in all phases of the Marine Corps Marksmanship Program during qualification and re-qualification. Additionally, they assist in the operation of firing ranges.