The previous chapters have presented summaries of the adoption of patient classification systems (PCS) in fifteen countries around the globe, starting with the US in 1983 and continuing through to Germany in 2005. The purpose of this final chapter is to stand back from the details of each country's experience with patient classification systems and analyze patterns of convergence and divergence in these experiences. The chapters describe some similarities, but also a great deal of variation in the definition, goals, and purposes of PCS from one country to the next as well as in the processes by which these systems were adopted. These differences lead us to ask the following questions: Why do some nations use PCS extensively, including, for example, as a payment method for health care providers, while others rely relatively little on these systems? What accounts for variation in the difficulty and duration of adoption and implementation of PCS across nations? What accounts for variation in the timing of adoption?Why have some nations just begun to use PCS, while others have used them for more than twenty years? Addressing these and related questions is important because the adoption and implementation of these systems remains incomplete both within and across nations. There may well be key lessons to be learned from examining adoption patterns, and these lessons can inform decision makers who are both current and potential users of this technology.