A catheter assembly may include a catheter adapter that includes a distal end, a proximal end, and an inner surface forming a lumen. The lumen may extend between the proximal end and the distal end. The catheter assembly may also include a cannula and a cannula hub. The cannula hub may include an outer portion disposed outside of the catheter adapter and an inner portion disposed within the catheter adapter. The cannula may extend distally from the inner portion. In response to the outer portion sliding proximally along an outer surface of the catheter adapter, the cannula may be withdrawn proximally into the catheter adapter. The outer portion may be configured to slide proximally to a locked position in which the cannula hub is locked with respect to the catheter adapter, and a distal tip of the cannula is disposed within the catheter adapter.