United States military occupation code

A United States military occupation code, or a military occupational specialty code (MOS code), is a nine-character code used in the United States Army and United States Marine Corps to identify a specific job. In the United States Air Force, a system of Air Force Specialty Codes (AFSC) is used. In the United States Navy, a system of naval ratings and designators are used along with the Navy Enlisted Classification (NEC) system. A system of ratings is also used in the United States Coast Guard.

Since an individual can obtain multiple job specialties, a duty military occupational specialty (DMOS) is used to identify what their primary job function is at any given time. An individual must complete and pass all required training for their military occupational specialty qualification (MOSQ).