Although immigrants' place in welfare state systems is of large relevance to academics and policymakers alike, there have been few attempts to compare immigrants' social rights in different countries at different moments in time systematically. This article presents the results from a comparative policy analysis that maps immigrants' access to seven different social programmes, in 20 different Western democracies, at four different points in time. The main findings are threefold. First, there are large differences in the extent to which different welfare states differentiate in benefit extension between immigrants and native‐born citizens. Second, over the last two decades, many countries have adjusted their welfare systems with the specific aim to accommodate immigrants, whereas many have also introduced punitive barriers that require immigrants to satisfy additional requirements. Third, these developments seem largely driven by politics: in particular, the adoption of punitive barriers has been more common in places where the political climate is more hostile to immigrants. These findings raise important questions about the future of social protection in an era of cross‐border mobility.