Medical technology, specialization, and the corporatization of health delivery systems in the late twentieth century have all helped give birth to an unwelcome but unavoidable responsibility for individuals with family or friends—serving as a health care proxy. The responsibility comes without monetary compensation, is often involuntary, and lacks any real guidelines beyond the duty to make life-and-death decisions in circumstances over which the proxy has little control.The parameters of the proxy's job have evolved somewhat awkwardly in statutes and case law, (...) as lawmakers and judges have tried to apply conventional concepts to novel circumstances. This article examines the legal and functional status of the proxy, as well as the strengths and weaknesses of current public policy as reflected by state advance directive and surrogate decision-making laws. The first section of the article provides a historical perspective of our current notions of agency law as relevant to health care proxies. (shrink)