This report presents the methodology and lessons learned from a climate change adaptation study conducted under the Greater Mekong Subregion (GMS) Core Environment Program. The study yielded a framework and methodology for assessing climate vulnerability and adaptation options for rural communities in the GMS. It was conducted in biodiversity conservation corridors in the Lao People’s Democratic Republic, Thailand, and Viet Nam during 2011–2012. The report introduces the framework, describes how it was applied, presents major results, and makes recommendations for future improvement.