The sustainable development goals agreed in March 2016 by the United Nations General Assembly set the global development agenda for the next 15 years. They include an ambitious target to reduce premature mortality from non-communicable diseases by a third by 2030. Premature mortality, defined by the World Health Organization as deaths occurring between the ages of 15 and 70, has gained broad acceptance in health research and policy over the past decade. We argue that it is explicitly ageist, reflecting institutional ageism in global health policy. Its inclusion in the sustainable development goals sends a strong signal in favour of discriminating against older people in the allocation of health resources and the collection of data. We consider the emergence of ageist approaches in global health policy and the potential effects of ageism in the sustainable development goals. We propose a less discriminatory approach.