This report explains the complex challenges facing the six countries in the renewables-rich Greater Mekong Subregion (GMS) as they work to implement a comprehensive framework to enable regional electricity power trading. Against the backdrop of energy market volatility, it details how ADB is helping high-voltage electricity network operators reach a deal on interconnections which could unlock extensive economic benefits for each GMS country. Acknowledging a transparent power-sharing regime is still some way off, it provides a road map to help countries overcome infrastructural challenges and political concerns to build a fully synchronized GMS transmission network.