Tear-away sheath introducers for catheters, methods for making such introducers, and methods for using such introducers are described. A splittable sheath introducer may include a sheath, a hub disposed at a proximal end of the sheath, a valve included with the hub, and a valve actuator movable from a first position to a second position, the valve actuator opening the valve when in the second position. The valve actuator may include a retaining member that enables the valve actuator to be retained by a portion of the hub when the sheath introducer is split apart.