This report draws on more than 1 300 government budgetary transfers and tax expenditures providing preferential treatment for the production and consumption of fossil fuels as documented in the 2020 OECD Inventory of Support Measures for Fossil Fuels to track progress in reform of support. It sets out principal trends across 50 OECD, G20 and European Union (EU) Eastern Partnership (EaP) economies, including as resulting from the COVID-19 crisis and novel sectoral decomposition of Inventory data. It reports on developments in tracking and monitoring fossil fuel support in the context of the G20 and the UN Sustainable Development Goals, and with respect to enhancing the interpretation of tax expenditure data. Finally, the report offers a sequential framework to assist governments assess and address the effects of fossil-fuel support measures and their reform, given ongoing challenges in gaining traction for reform.