What is the state of the art and science with regard to professional development for principals? What is the status of principal professional development in the four-state region of Kentucky, Tennessee, Virginia, and West Virginia? This policy paper attempts to answer these two questions through a review of the literature, seven interviews, and a document review concerning professional development practices for principals in the region. It concludes with implications for policymakers and recommendations. [This document was produced by the Appalachia Educational Laboratory at Edvantia, formerly the Appalachian Educational Laboratory (AEL, Inc.).]