Additionality, the condition that MDB interventions have a positive impact on development, while not crowding out other market participants, by supplying inputs – financial and non-financial – which cannot be provided better from other sources, has recently gained increased attention, both from MDB shareholders and evaluators. Participants will learn about the similarities, differences, gaps and potential synergies in MDBs’ mandates, operational approaches and evaluation approaches to additionality. The panel interventions will focus on challenges in evaluating additionality in their respective institutions.