Clean electricity is a key milestone on the road to net zero. To achieve this goal, coal and fossil gas generation need to be phased out urgently. This report develops a 1.5°C compatible pathway for fossil gas generation in South Korea’s power sector and two phaseout schedules for the country’s gas fleet prioritised by cost and health which meet this pathway.South Korea’s power sector is dominated by fossil fuels, which provided over 60% of generation in 2021. While plans are being developed to reduce fossil gas consumption, current policies are not ambitious enough. Under the 10th Basic Electricity Plan, fossil gas would still provide 23% of electricity in 2030. This does not align with the Paris Agreement’s 1.5°C limit.