Demographic, socio-economic, and political trends throughout the developed world have contrived to make elder care an issue of utmost policy importance. They also have led to sharp reductions in health and social program expenditures. Policymakers are looking to communities to help meet growing care needs because community care is believed to be better and cheaper than institutional care. However, these beliefs become untenable when costs beyond public sector costs are considered. In fact, informal care carries a number of hidden costs that seldom are considered in health and social policy discussions. This article introduces a taxonomy of the costs of informal elder care, which can be categorized as out-of-pocket expenditures, foregone employment opportunities, unpaid labor, and emotional, physical and social well-being costs. Then, an illustration is provided regarding how the taxonomy can be applied to understanding the incidence, magnitude, and distribution of these costs among stakeholder groups. This taxonomy can help inform ongoing debate about health and social policy reform.