REDD+ interventions can help both people and forests adapt to climate change by conserving or enhancing biodiversity and forest ecosystem services. However, additional adaptation measures might be needed, such as the protection of agriculture and livelihoods and the development of fire management strategies. Such measures could support the sustainability of REDD+ interventions and the permanence of carbon stocks by preventing activity displacement and induced deforestation and by limiting or avoiding damage to livelihoods and ecosystems from extreme weather events. This guidebook demonstrates how community-based adaptation (CBA) can be integrated into REDD+ interventions and other mitigation activities through a 5-step approach. In addition to vulnerability analysis, a combination of participatory and analytical methods is proposed to capture the voices of multiple stakeholders at the community and broader levels and examine the linkages between adaptation interventions and REDD+. Special emphasis is placed on forest resources and forest management to explore the potential costs and benefits of adaptation interventions for effective REDD+ implementation. Case-studies from Indonesia and the Philippines demonstrate how the steps can be followed. The case study activities and the production of this guidebook were made possible by the financial contribution of the German Federal Ministry for Economic Cooperation and Development (BMZ) and the technical and logistical assistance of the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ).