[영문]Existing research suggests that models of enhanced primary care lead to health care systems with better performance. What the research does not show is whether such an approach is feasible or likely to be effective within the U.S. health care system. Many commentators have adopted the model of the patient-centered medical home as policy shorthand to address the reinvention of primary care in the United States. We analyze potential barriers to implementing the medical home model for policy makers and practitioners. Among others, these include developing new payment models, as well as the need for up-front funding to assemble the personnel and infrastructure required by an enhanced non-visit-based primary care practice and methods to facilitate transformation of existing practices to functioning medical homes.