A two-piece catheter securement system has a fixation pad with an adhesive undersurface and an antimicrobial flap. On an upper surface of the pad are cooperative first attachment members. An upper capture and retention shell has an outer shell wall. The first and second ends of the shell may have a plurality of slots for capturing and retaining administration and catheter tubing. The shell has an inner shell ceiling having a plurality of spaced apart second attachment members thereon. The first and second attachment members are aligned to cooperatively engage when the shell is urged into releasable engagement with the pad with the slots capturing and retaining the tubes.