text: in the military what is a "mos"? i was just wondering cause my hubby is national guard army activated right now. i know what unit he is in. if he is artillery is that his mos? or is it infantry? i always wondered just forgot to ask hubby. people ask me this question and i never know lol. its different for us wives who had never lived on base and he has only been in a year. thanks in advance. have a nice day. mos = military occupational specialty.. a nice system to label a job in quick alpha-numberic manner.  used by the army, air force, and marines.  an individual may hold numerous mos'... for their primary occupation, and then for subsequent qualifications and schools.  nec = naval enlisted code  (similar to mos, only numeric)