 The segregated model of clinical research was designed to protect research participants from exploitation. The primary drawbacks are that it is inefficient and it raises concerns over free riders, allowing patients to realize the benefits of improved clinical care without having to accept any of the risks associated with its generation. Learning health care systems are intended to address the problem of inefficiency. Given that all the members of learning health care systems are possible research participants and also beneficiaries of research, they may, in the process, address concerns over free riders. 