Effective policy implementation and inter-state solidarity remain elusive in migration, an area European citizens identify as a key challenge for the EU. I hypothesise that EU migration funding could contribute to addressing these problems. I will test this hypothesis through an original combination of legal and empirical methods. I will undertake a cross-policy (migration and cohesion policies) and comparative (Greece and the Netherlands) analysis of the legal design and administration modes of two types of EU funding: Migration Funds, and Structural and Investment Funds. I will adopt an interdisciplinary approach, combining theoretical concepts of EU constitutional and administrative law, such as federalism and an integrated European administration, with theories of political science, such as polycentric and multi-level governance. I will combine doctrinal legal research with empirical qualitative research, incorporating findings through semi-structured interviews with institutional and civil society experts at EU level, the Netherlands and Greece. Through an evidence-based evaluation of EU funding’s impact to steer policy implementation and realise inter-state solidarity, my research will yield proposals to reform EU migration funding. Conceptually, I will analyse how the changing nature of the European administrative system is revealed through the management of EU funding, theorising the implications of EU funding’s operationalisation modes for the nature of the EU integration project. The project will advance scientific debates on federalism, governance and public policy. Beyond the scientific community, the research will impact policy and practice. Its implementation will create intersectional synergies with societal partners (civil society, national administrations, EU institutions); evidence-based proposals for the reform of EU funding will have an impact beyond academia; and the comparative character of the research will allow policy-makers and administrators to benefit from the insight and experience of different jurisdictions. Finally, communication actions targeting public audiences will raise awareness of EU funding’s role in migration governance.