A humeral cut guide system for resectioning or resurfacing a humeral head. The humeral cut guide system includes a primary cut guide member configured to be removably coupled to the humeral head. The primary cut guide member includes a patient-specific bone-engaging surface, a primary elongate slot that defines a primary cutting plane, and a pair of cylindrical apertures configured to receive a pair of guide pins. A secondary cut guide member includes a pair of through-holes configured to mate with the pair of guide pins, and the secondary cut guide member includes a secondary elongate slot that defines a secondary cutting plane.
