 The ethical challenge learning health care systems face is whether it is possible to do away with the segregated model, along with its regulations and practices, without reintroducing the potential for participant exploitation. For example, should individuals in a learning health care system be told that their data might be used for research purposes? Should they be notified when it is? To what extent can patients in learning health care systems be exposed to added risks for the purposes of research? Should they be permitted to decline being so exposed? In the end, then, on-going attempts to address the concerns raised by clinical research raise new ethical concerns and, thereby, offer opportunities for philosophers and others looking for interesting, not to mention practically important issues in need of analysis and resolution. 