Innovations in health care account for some of the most dramatic improvements in population health outcomes in the developed world as well as for a nontrivial proportion of growth in expenditures. Provider organizations are the adopters of many of these innovations, and understanding the factors that inhibit or facilitate their diffusion to and possible disengagement from these organizations is important in addressing cost, quality, and access issues. Given the importance of these issues, the purpose of this article is to (1) create a comprehensive census of studies examining the adoption of and disengagement from innovations in health care provider organizations; (2) organize these studies into an inductively derived classification scheme; (3) assess the studies' strengths and weaknesses; and (4) reflect on the implications of our review for future research.