While health inequalities among older people have long been a research focus and are now high on policy agendas in developed societies, they have often been neglected in less developed ones, despite them experiencing rapid population ageing since the turn of the century. Using data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) cohort study (N = 63,578), this paper measures the health status of older people using the Quality of Well-Being scale, and estimates time trends in health inequality with concentration indices, followed by an investigation of their social determinants. Its specific focus is health care accessibility (HA) in the period 2005–2018, when China experienced an unprecedented advance in health-related social policy reform. The analysis reveals pro-rich inequalities in health among older people, but also shows that these have narrowed gradually over the past two decades, which is largely attributable to greater equity in access to health care. Within this general trend of inequality reduction, however, the role of HA has declined and social determinants such as education now have an increasing influence on health inequalities. These findings suggest that social policies targeting not only health improvements among older people but also health inequalities earlier in the life course are required if policy makers want to promote health equity in later life.