Abstract Starting from the idea that border externalization – understood as the spatial and institutional stretching of borders – is enmeshed with the highly contextual humanitarian and securitarian dynamics of migrant trajectories, this article addresses the reach of border externalization tentacles in Costa Rica. Although Costa Rica does not formally engage in border externalization agreements, it is located in a region characterized by transit migration and transnational securitization pressures. Moreover, externalization efforts across the Atlantic have contributed to a relatively new presence of so-called extra-continental migrants. Given these circumstances, we aim to interrogate the ways in which border externalization plays a role in Costa Rica’s discourses, policies and practices of migration management. We do so by analysing a migrant reception centre in the northern Costa Rica border region, and by focusing on African transit migration. Our analysis is based on exploratory field research at the centre as well as on long-term migration research in Central America. Building on these empirical explorations and the theoretical notions of mobility regimes, transit and arterial borders, the article finds that Costa Rica’s identity as a ‘humanitarian transit country’ – as enacted in the migrant reception centre – both reproduces and challenges border externalization. While moving towards increased securitization of migration and an internalization of its border, Costa Rica also distinguishes itself from neighbouring countries by emphasizing the care it extends to African migrants, in practice enabling these migrants to move further north. Based on these findings, the article argues for a deeper appreciation of the role of local-regional histories, perceptions, rivalries, linkages and strategies of migration management. This allows for a better grip of the scope and shape of border externalization across a diversity of migration landscapes.