We discuss the conceptual foundations of measuring (in)equity in health and health care. After an overview of the recent developments in the measurement of socioeconomic inequalities and in racial disparities, we show how these partial approaches can be seen as special cases of the more general social choice approach to fair allocation and equality of opportunity. We suggest that this latter framework offers many new analytical possibilities and is sufficiently rich to accommodate various ethical views. We emphasize that horizontal and vertical equity are intricately linked to each other. We then argue that a focus on overall well-being is necessary to put the partial results on health (care) inequity into a broader perspective, and we discuss the pros and cons of various methods to evaluate the joint distribution of health and income: multidimensional inequality indices, dominance approaches, the use of happiness measures, and finally the concept of equivalent income. Throughout the chapter the theoretical analysis is complemented with an overview of recent empirical results.