Abstract: A method of implanting a humeral component includes accessing a humerus and resecting a head portion of the humerus to form a resected surface. The method further includes selecting a first combination sizer and guide device having an outer surface sized complementary to a desired implant head size, positioning the selected first combination sizer and guide device on the resected surface, guiding placement of a guide pin in the humerus with the first combination sizer and guide device, guiding a reamer with the placed guide pin to form a reamed cavity in the humerus, positioning an anchoring portion of a humeral implant base portion in the reamed cavity, positioning the first combination sizer and guide device on the base portion, removing the first combination sizer and guide device from the base portion, and positioning an implant head on the base portion.