Battalion Aid Station The Battalion Aid Station is a medical section within a battalion ' s support company in the military of the United States , specifically , the Army and Marine Corps . As such , it is the forwardmost medically staffed treatment location . During peacetime , it is led by a Medical Operations Officer , a First Lieutenant in the Army Medical Service Corps or a Lieutenant from the Navy Medical Corps . During combat , a commissioned medical doctor with the Army Medical Corps may assume leadership of the platoon and direct medical operations . However , in the Army , the Medical Service Officer normally retains control of training , planning , and administration of the platoon while the doctor in charge directs medical care . The primary mission of the Battalion Aid Station is to collect the sick and wounded from the battalion and stabilize the patients ' condition . The Battalion Aid Station belongs to , and is an organic component of , the unit it supports . It may be split into two functional units for up to 24 hours , the Main Aid Station consisting of the medical doctor and three 68W combat medics or 8404 corpsmen and a Forward Aid Station consisting of the Physician Assistant and three more 68Ws or corpsmen . This allows the section to support more than one unit or care as the unit advances or withdraws . According to the Geneva Convention , military medical facilities , equipment and personnel are non - combatant s and may not be attacked as long as they remain in a non combatant role . Medical personnel are allowed weapons for the purpose of self - and patient - defense . Army Battalion Surgeon . A battalion surgeon is the chief medical officer of a military battalion in the Army or Marines . Despite the name , most battalion surgeons are primary care physicians , i . e . emergency medicine , family medicine , pediatrics , or internal medicine or general medical officers , and are not actual surgeons who perform invasive surgical operations . The term " surgeon " is a holdover from the U . S . Military ' s British colonial past . The British military uses the term " surgeon " to mean a physician attached to a " front line " unit . While the Navy department still uses the GMO or General Medical Officer physician to man many BAS , the Army has worked to eliminate GMO ' s and fill most BAS with " residency trained physicians " . A GMO is a physician that has completed medical school and a one - year " internship " that allows them to receive an independent medical license in the US . GMO ' s have a limited resource of medical knowledge and experience . The battalion surgeon is a special staff officer who advises the battalion commander on matters pertaining to the health of the battalion . Chief duties include responsibility of managing a battalion aid station ( BAS ) , medical supervision of the Battalion PA ( Physician Assistant ) , performing sick call for members of the battalion , and supervising the medical planning for deployment . The battalion surgeon carries the United States Army rank of Captain ( O - 3 ) , Major ( O - 4 ) , or Navy rank of Lieutenant ( O - 3 ) or Lieutenant Commander ( O - 4 ) . During peace time , a limited amount of Army Battalions actually have a physician or Battalion Surgeon . The exception is Aviation , Special Operations , or Stryker Brigade Support Battalions ; which routinely have a Battalion Surgeon . Since physicians are usually in short supply and expensive to employ , most Battalions have a PA ( Physician Assistant ) that performs the duties of " primary care physician " for the members of the Battalion . If a Battalion is " authorized a physician " during a deployment , then the PROFIS ( professional filler system ) is used to pull a military physician from a military hospital to deploy with the Battalion and serve as the Battalion Surgeon . A TDA / MTF ( medical treatment facility ) physician usually wears a uniform , but they do exactly the same job as a civilian physician . A TDA physician sees military dependents , active duty patients , and retirees . During peace time the PROFIS system is in place , but rarely used . Since the start of Operation Iraqi Freedom and Operation Enduring Freedom ( Afghanistan ) the PROFIS system is used routinely . Doctors are " PROFIS " or pulled out of the MTF ' s in a type of lottery system that factors in the number of deployments the physician has been on , their specialty , and the length of time of the PROFIS assignment . Since most of the Physicians tapped to be PROFIS Battalion Surgeons have been in primary care fields , the Army has had a hard time retaining or recruiting physicians with those specialties . Marine Corps Battalion Aid Station . Because of the strictly combatant role of the Marine Corps , the Marine Corps does not have organic medical personnel and the Navy supplies medical officers and hospital corpsmen for them . As with the Army , the battalion surgeon is the chief medical officer in a Marine battalion . The battalion surgeon is a staff officer who advises the battalion commander on health and medical matters pertaining to the battalion . A battalion surgeon carries the United States Navy rank of Lieutenant ( O - 3 ) or Lieutenant Commander ( O - 4 ) . The staffing of a Marine Corps BAS is slightly different from the Army . The battalion surgeon technically manages the BAS including the Assistant Battalion Surgeon , either a Medical Officer or physician assistant Medical Service Officer as well as corpsmen . The BAS may also be manned by Independent Duty Corpsmen , a corpsmen trained to function independently of a medical officer and who function much in the same way as a physician assistant . A Chief Hospital Corpsman , known as the Battalion Chief , is also usually part of a BAS and supervises the other corpsmen .