This policy brief examines the relationship between adaptive social protection and displacement governance, arguing that the next frontier of reform lies not only in greater shock-responsiveness, but in stronger horizontal integration across systems. Adaptive social protection has made major advances in strengthening governments’ capacity to scale assistance during crises through social registries, adaptive financing, anticipatory action, and delivery systems. Yet displacement presents a distinct governance challenge because vulnerability is experienced across administrative jurisdictions, legal categories, sectoral systems, and phases of crisis and recovery. Using Southeast Asia as the primary analytical ground, the brief contrasts Indonesia’s social protection architecture, centred on DTKS, with Thailand’s Health Insurance Card Scheme, showing how different systems address different dimensions of institutional adaptation. It argues that sustainable inclusion depends not only on displaced populations gaining access to national systems, but on those systems maintaining continuity of protection as people move. The brief concludes with priority actions for governments, social protection agencies, development partners, policymakers, ministries of finance, and subnational authorities to strengthen displacement-inclusive system design.