RESUMEN
The Patient Protection and Affordable Care Act of 2010 provides for a number of major payment and delivery system initiatives. These potential changes need to be tested, scaled, and adapted with an urgency not evident in previous demonstration projects of the Centers for Medicare and Medicaid Services. We discuss lessons learned from our iterative tests of care reengineering at Geisinger--specifically, through our advanced medical home model, ProvenHealth Navigator, and the way we continuously modified the model to improve quality and value. We hypothesize that the most important ingredient in our model has been the embedding of nurse case managers into our community practices and the real-time feedback of data on the use of health services by the most complex patients.