In this article, the author documents the illness and health care problems facing indigenous communities in Baja California, Mexico, by using ethnographic data from research she conducted from 1999 to 2001 with rural, indigenous Kumiai and with their primary health care providers in urban Ensenada. The author contends that barriers to care are structural and social, rather than constituted of competing ideas of illness causation and treatment. A history of multiple medical systems and hierarchical social relations work in concert to produce specific patterns of health care problems for indigenous communities. Multiple medical systems in Mexico rarely result in clearly differentiated models of health care, however. Individual health care beliefs and behaviors frequently blend Western allopathic, or biomedical, beliefs and behaviors with those of homeopathy, herbalism, and different spiritual healing traditions. The primary health care problem that faces indigenous communities is that health care, however defined, is frequently unavailable and rarely comprehensive. Nevertheless, most of their health care providers frequently presume that poor indigenous health is largely a result of competing indigenous illness and health care beliefs. Indigenous health and health care problems are largely a result of economic and ethnic marginalization, as the case of Don Ricardo demonstrates. (Contains 1 table and 9 notes.)