A long and healthy life is universally valued. The starkest inequalities in later life are how many years of life remain at an older age such as 65 years, and how many years of life that remain free from disabilities that impede physical, cognitive, and social functioning to the extent that they limit the sense of valuing one’s life. In this chapter we apply the frame of social determinants of health, using the life course approach to understand inequalities in health in later life. Healthy ageing is patterned by degrees of social advantage. Biological ageing, as revealed by physical and cognitive changes, is slower in people in better socioeconomic circumstances. These inequalities in health in later life need to be understood in terms of current social, economic, environmental conditions of living, as well as previous experiences and living conditions across the life course that affect the biological processes of ageing.