Due to the high financial cost of employing physicians, civil engineers, lawyers or other "high dollar specialists" in a military unit, usually at the battalion and sometimes at the brigade level a full time "specialist" is not permanently assigned to these units.
When a unit deploys to an austere location, the demand for a specialist increases.
Medical professionals are usually assigned to military hospitals or clinics, where they see patients, exactly like civilian providers.
As a unit surgeon, the physician can expect to do administrative as well as clinical duties.
[1] Medical and surgical subspecialists may be assigned PROFIS to combat support hospitals (CSH).