Tactical remote sensor system (TRSS) maintainers are trained to inspect, maintain and repair TRSS equipment up to the field level. TRSS maintainers are also trained to provide technical assistance during the installation and operation of the TRSS. This MOS will only be assigned to Marines holding primary MOS 2846, or 2862.

Electronics maintenance technicians are qualified to perform complex diagnosis, repairs, and modifications to ground data/communications equipment. These technicians supervise ground data/communications maintenance activities and instruct in the use and repair of ground data/communications equipment and systems. Typical duties include complex repairs and modifications to data/communication equipment, supervision of a maintenance section or shop, coordination of equipment evacuation for repair with other maintenance activities, requisitioning of parts, and monitoring maintenance reports. These technicians also provide technical assistance during the employment and installation of data/ communication systems. This MOS is a career progression for MOSs 2844, 2846, and 2847. Preferred target for assignment to career progression training is at the 6-8 years time in service (TIS) mark. MOS 2891, Electronics Maintenance Chief, is assigned upon promotion to Master Sergeant.

Calibration technicians are qualified to perform calibration of high density, low complexity test measurement and diagnostic equipment (TMDE). Additionally, they are also qualified to repair and modify electrical/electronic TMDE. Typical duties include the calibration of high density, low complexity TMDE and the repair and modification of electrical/electronic TMDE as necessary to include associated maintenance management and metrology documentation. These technicians are also qualified to instruct theory and maintenance of electrical/electronic TMDE.

Metrology technicians are qualified to calibrate precision electronic, mechanical, physical, optical, infrared, and laser Test Measurement and Diagnostic Equipment (TMDE) through use of higher order measurement standards. Typical duties include supervising the operation of a calibration and TMDE maintenance facility to include such tasks as safeguarding and reporting of calibration results, maintaining accurate traceability to a higher echelon laboratory, and preparing and receiving shipments of delicate TMDE. Duties also include the determination of calibration levels required based on equipment capabilities and user requirements, technical evaluation of calibration procedures, monitoring the capability of requirements of facility standards and submission of change requests, and the training of users in the proper care and operations of TMDE. This MOS is a career progression for MOS 2871. Preferred target for assignment to career progression training is at the 6-8 years time-in-service (TIS) mark.

Artillery electronics technicians' duties encompass the operation and maintenance of Counter Mortar Radar Systems, Meteorological Measuring Systems, Chronograph Systems, and ancillary ground radar systems. Tasks include the siting, installing, inspecting, testing, and repairing of the systems with emphasis on inspection. Artillery electronics technicians maintain necessary records on maintenance performed, hours of operation, and systems or component tests. MOS 2891, Electronics Maintenance Chief is assigned upon promotion to Master Sergeant.

Electronics maintenance chiefs perform staff duties in formulating and implementing maintenance and supply plans, provisioning data/communications items, and preparing or reviewing publications and training materials. As a senior noncommissioned officer in a highly technical field, the electronics maintenance chief is qualified to manage the activities of maintenance personnel from diverse maintenance specialties within the MAGTF. Duties may include teaching electronics theory and maintenance best-practices, supervising a maintenance shop, writing evaluation test plans, and inspecting units performing electronic maintenance. This MOS is a career progression for gunnery sergeants with MOSs, 2831, 2834, 2862, and 2887.