© Cambridge University Press 2019. Internationally, in-work benefits (IWBs) are widely adopted as a measure to assist parents transitioning to work and to 'make work pay' for low-income families. The family income supplement (FIS) is an Irish IWB, introduced at a time of rapid societal change. This article shows how changing family dynamics, and a shift in policy focus towards a 'work-first' approach, challenged the original values underlying FIS. We discuss FIS in the context of changes to family life and social policy. We then outline the results of ten interviews with experts using three themes: work-first approach, child poverty and encouraging care. Our analysis shows that policymakers faced new challenges to provide an income support for children while also promoting full-time labour participation. FIS continues to support working families, but in a manner that creates contradictions for the contemporary 'work-first' approach. It is necessary to re-examine FIS in relation to its wider policy context and to address requirements for caring.