The U.S. Department of Energy (DOE) Biomass Program’s National Algal Biofuels Technology Roadmap was prepared with the input of more than 200 scientists, engineers, industry representatives, research managers, and other stakeholders, this document represents the synthesis of the Biomass Program’s National Algal Biofuels Technology Roadmap Workshop, comments gathered during a public comment period, and supporting scientific literature. This Roadmap is intended to summarize the state of technology for algae-based fuels and document the research and development challenges associated with producing them at a commercial scale.