This introduction reviews the contributions this collection of articles makes to understanding migration, social reproduction and social protection. Migration necessarily involves reconfigurations of family relations and these entail changes in the patterning of social (in)security. Our expansive interpretation of the concepts of social reproduction and social protection situate the reorganisation of gendered family lives as integral to the migration-development nexus. Life-course thinking informs analysis of how migrants 'do family' and what this means for gender, identity and (in)security. The collection explores how 'care deficits' are managed, both discursively through the negotiation of gendered ideologies about gender identity and the family, and through the everyday practice of social reproduction. The resulting reorganisation of social security involves taking on new risks and vulnerabilities for migrants and their families. For both internal and international migrants the challenges involved in securing social reproduction are powerfully shaped by welfare and migratory regimes and raise important questions about the relationship between social protection and broader social policy and citizenship issues.