A sheath introducer for a catheter includes a sheath having a lumen, a hub positioned on a proximal end of the sheath, and a housing positioned on the hub. The hub can include a splittable penetration member having a port in fluid communication with the sheath lumen. The housing can include a valve having a closed upper surface and a channel surrounding the splittable penetration member. Movement of the housing with respect to the hub can expose the port of the splittable penetration member for insertion of the catheter.