Tactical evacuation occurs when moving patients from one of the forward surgical teams or where patients have had life and limb threatening surgery to a combat support hospital, fleet hospital or expeditionary medical hospital where more assets are available including subspecialty care like neurosurgery. This evacuation is done by all three services but the majority is performed by army and navy nurses and medics or corpsman sent from the originating facility with the patient. In the sustainment phase we are in now patients are sometimes brought directly from a Level 1 to a Level 3 facility.