Living arrangements are a key dimension of quality of life and well-being in old age. Availability of family care, as well as social and economic support, is in part a function of whom you live with. In order to be able to forecast future changes in household composition, particularly in relation to planning and targeting particular community care services, information is needed on the probability of a person experiencing a change in their living arrangements, and the life course events that may act as triggers for such changes. This article uses data from the British Household Panel Survey (1991-99) to analyse the dynamics of living arrangements in later life.