Research on the division of family work has focused on household work and child-care to the exclusion of other domains, whereas studies on care-giving for older people typically ignore spouses' support to care-givers. In this paper we apply an approach that is typical of research on spouses' division of family work in caring for parents, in that the theoretical model focuses on the ‘cultural mandates’ that guide spouses' division of care, namely gender ideologies about appropriate roles, kinship obligations, and taboos against cross-gender personal care. Other predictors of the spousal division of care drawn from economic and health-care utilisation models are also examined. The analyses use pooled data on 1,449 care occasions from the first five waves of the US Health and Retirement Study. It was found that most couples to some extent share parent care, and that the involvement of husbands depended on a complex interplay of cultural mandates and contexts. Husbands participated most in personal care for parents if the care was mandated by kinship obligations (they cared more for their own than their wife's parents), and by cross-gender care taboos (they cared more for fathers than mothers). Other cultural contexts (such as race), a spouse's other commitments, health-related ability, resources (including support from the parents' other children), and care-burden also played a role. The findings demonstrate that decisions to care for parents emerge from complex negotiations among spouses and their children and siblings or, in other words, that parental care is a family endeavour.