STAP and UNEP's Global Programme of Research on Climate Change Vulnerability, Impacts, and Adaptation initiated a process to assess the state of knowledge on the monitoring and evaluation (M&E) of climate change adaptation (CCA). This report reflects the synthesis of efforts over the past two years in that area, and draws from a wide base of knowledge regarding the current state of national and multilateral actions on adaptation, the outcomes of the Paris Agreement, and the needs and priorities of the GEF.