In this paper, I examine the implications of welfare and migration policies on transnational aged care arrangements of older migrants in Australia. The paper draws on the results of an ethnographical, biographical and network analytical study of transnational social support networks of older migrants in Perth. I present the developed typology of older migrants and their possibilities of transnational care through three case studies that exemplify each type, namely `retirement migrant by choice', 'financial obstacles of traditional labour migrants', and 'mobility and welfare regime restrictions of refugees'. The case studies show, first, that the maintenance of social ties across national borders through which different forms of care are organised is constrained by the Australian mobility regime, where temporary migration schemes prevail and migration policies are increasingly restrictive. Second, transnational social support is affected by a welfare regime that is increasingly linked to the mobility regime, as the rights to social welfare and long-term care are often linked to citizenship. Third, inequalities in the possibilities of transnational care and inaccess to mobility are linked to migrants' legal and socioeconomic status in the country of settlement and the position of their country of origin in the global geopolitical hierarchy. Based on these findings, I propose a 'regimesof-mobility-and-welfare' approach for the study of transnational social support and family care, which considers the effects of 'sedentary' policies and the intertwinement of mobility and welfare regimes.