Marital status and living arrangements, along with changes in these in mid-life and older ages, have implications for an individual's health and mortality. Literature on health and mortality by marital status has consistently identified that unmarried individuals generally report poorer health and have a higher mortality risk than their married counterparts, with men being particularly affected in this respect. With evidence of increasing changes in partnership and living arrangements in older ages, with rising divorce amongst younger cohorts offsetting the lower risk of widowhood, it is important to consider the implications of such changes for health in later life. Within research which has examined changes in marital status and living arrangements in later life a key distinction has been between work using cross-sectional data and that which has used longitudinal data. In this context, two key debates have been the focus of research; firstly, research pointing to a possible selection of less healthy individuals into singlehood, separation or divorce, while the second debate relates to the extent to which an individual's transitions earlier in the life course in terms of marital status and living arrangements have a differential impact on their health and mortality compared with transitions over shorter time periods. After reviewing the relevant literature, this paper argues that in order to fully account for changes in living arrangements as a determinant of health and mortality transitions, future research will increasingly need to consider a longer perspective and take into account transitions in living arrangements throughout an individual's life course rather than simply focussing at one stage of the life course.