The paper explores the implications for health policy of the segmentation of society into social groups with very different levels of income and wealth. It focuses particularly on societies undergoing rapid social change, such as Southern Africa and China. Governments can influence access to health benefits, to some extent. However, they are unlikely to achieve equality in the consumption of health goods, whilst access to all other is very unequal. They need to identify how to use their limited powers to reduce the most damaging health inequalities. This is particularly important in societies where social groups are re-negotiating their relative entitlements to health benefits.