The 0111 Administrative MOS is likely the most versatile and commonly found specialties in the Marine Corps. Responsible for all clerical and administrative tasks, Admin Specialists can be found in unit Admin shops, Installation Personnel Administration Centers, and headquarters elements. No government entity can function without personnel to handle paperwork, and there is virtually no component in the Marine Corps without 0111's assigned. Marines may hold this primary MOS from Private through Master Gunnery Sergeant.

Administrative Specialist responsibilities include the management of administrative and clerical functions in the areas of general administration, personnel administration, operational administration, and manpower administration. The required qualifications include basic clerical and communication skills. Administrative Specialists are required to learn administrative procedures and processes, pay and personnel information, preparation of orders and directives, correspondence, and the use and maintenance of filing systems. The civilian equivalent of an 0111 is a Human Resources specialist.