In an effort to promote the production, distribution, and use of biofuels in the United States, Congress created the Renewable Fuel Standard (RFS) program through the Energy Policy Act of 2005, as modified by the Energy Independence and Security Act of 2007. The RFS essentially mandates an increasing use of biofuels for transportation in the U.S., and places the burden of compliance on fossil fuel refiners and importers. The RFS has been quite controversial, and Congress is currently considering legislation that would either repeal or significantly rollback the program. This article reviews the various “generations” of biofuels, and explains critical distinctions between food-based biofuels (like corn starch-based ethanol), which have been the focus of most of the criticism of the RFS, and “truly advanced biofuels” that could potentially be far superior in terms of overall environmental impact, including but not limited to a reduction in greenhouse gas emissions. The article describes a number of setbacks that have been experienced in the EPA’s efforts to implement the RFS, including lagging development of cellulosic biofuel technology, the 10% ethanol blend wall, pervasive fraud in the market for renewable identification numbers (RINs), and EPAs repeated failure to comply with statutory deadlines in promulgating Renewable Volume Obligations (RVOs). Unintended negative environmental impacts of biofuels are also discussed. The article concludes by proposing a number of actions that could serve to promote the overall policy objectives of the RFS.