This paper investigates the potential relevance to health care reform of the Nobel Prize-winning research of Elinor Ostrom on community-based management of natural resource commons. Two related interpretations of the concept of a “health commons” are considered, the first (a micro-commons) consisting of specific programs of quality improvement or health promotion, and the second encompassing the entire system of physical, financial, human, and social resources relevant to the delivery of health care in a region. The proliferation of micro-commons has deepened the fragmentation of health care delivery systems, and rising costs of health care threaten the long-term sustainability of this mode of delivery. Cross-stakeholder collaborations can serve as “stewards” of either of these health commons, under conditions analogous to the Design Principles identified by Ostrom. Examples from the case of Grand Junction, Colorado, are used to illustrate the relevance of these principles to shared stewardship of a regional health commons. The paper concludes with a set of questions that can help assess a community’s ability to more effectively manage their own system of health care delivery.