Thailand was one of the first Asian countries with a comprehensive feed-in tariff program, with streamlined interconnection regulations adopted by the Thai Cabinet in 2002 and technology-specific tariff ‘Adders’ in 2006. This paper presents an overview of the country’s feed-in tariff, or Adder, program and its development. As of December 2011, Thailand has about 8000 MW of renewable energy projects in the pipeline seeking Adder and about 1000 MW already connected and selling power to the grid. Thailand’s feed-in tariff program has undergone significant transitions especially since 2010 in tariff levels and screening criteria partly in response to applications for 471 solar electric power plants exceeding 2000 MW. A powerful new oversight committee comprising utility and Ministry of Energy representatives has raised concerns regarding transparency and consistency, and significantly reduced approval rates of new applications.