A report from the Brookings Institution makes the case for the importance of 21st century skills as goals for education systems and provides international examples. It focuses specifically on the development of new assessment methods as a primary means to help countries integrate 21st century skills – such as critical thinking, problem solving, collaboration, and communication – into curricular reforms. The report is a review of research and a policy analysis rather than an empirical study. Its main contributions are (a) the identification of three challenges to implementing a 21st century skills agenda, and (b) the organization of key ideas and research to possibly address those challenges. Policymakers should find the report useful as an overview highlighting the importance of 21st century skills internationally, although the report’s omission of discipline-specific considerations makes it less helpful as a guide for local curricular and pedagogical reforms.