A consortium of employers and managed health care organizations has come together to test the feasibility and usefulness of an outcomes management system, a new strategy for providing information on what types of medical care are effective, for whom, and under what circumstances. Systematic measurement of health outcomes can provide the information that patients, providers, and insurers/employers need to make informed choices among alternative treatments and services. A pilot project in thirteen sites found that outcomes management is feasible for evaluating ongoing care for chronic conditions but is difficult to apply for short-term diagnostic or treatment episodes. Further, successful implementation requires a commitment of substantial organizational resources.