SOST is GST and FST. In the air force there is (GST) Ground Surgical Teams. All ground Surgeons who deploy to temporary Medical Facilities (almost always in a war zone), outside of full service hospitals with specialists. GST has a (Surgical/Medical Hospital) close to forward deployed Special Ops Units. Its more like just an Operating room + Some communications and extra equipment that a team can't carry to the field. Its usually in a tent or those military cargo container/trailer looking buildings. SOST is the Foward Surgical Team which would deploy from the forward facility to do surgery on the battlefield, some cases they even do it during a gun fight. The Navy and Army are now both combining and integrating servicemembers to make a nearly identical unit with the similar crew member make-up.