A SAFETY IV CATHETER INCLUDES A UNITARY, RESILIENT NEEDLE GUARD RECEIVED IN A CATHETER HUB (26). THE NEEDLE GUARD INCLUDES A PROXIMAL ARM OR WALL THAT INCLUDES AN OPENING THROUGH WHICH A NEEDLE (16) PASSES FOR AXIAL MOVEMENT. WHEN THE NEEDLE (16) IS RETRACTED FROM THE CATHETER, IT RELEASES THE FORCE THAT HAD PREVIOUSLY PREVENTED MOVEMENT OF THE NEEDLE GUARD WITHIN THE CATHETER HUB (26). THIS IN TURN CAUSES THE NEEDLE GUARD TO SNAP INTO A POSITION IN WHICH IT IS CLAMPED ONTO THE NEEDLE SHAFT AND IN WHICH ITS DISTAL WALL BLOCKS ACCESS TO THE NEEDLE TIP (18). IN THIS CONDITION, THE SPRING NEEDLE GUARD AND NEEDLE (16) CAN BE REMOVED FROM THE CATHETER HUB (26). A SLOT OR CRIMP MAY BE FORMED IN THE NEEDLE SHAFT THAT ENGAGES WITH THE NEEDLE GUARD AFTER THE PROTECTED NEEDLE AND NEEDLE GUARD ARE REMOVED FROM THE CATHETER HUB (26), THEREBY TO PREVENT REMOVAL OF THE PROTECTED NEEDLE FROM THE NEEDLE GUARD.