The U.S. Government Accountability Office (GAO) was asked to review the potential economic effects of climate change and risks to the federal government. This report examines methods used to estimate the potential economic effects of climate change in the United States, what is known about these effects, and the extent to which information about these effects could inform efforts to manage climate risks across the federal government. GAO reviewed 2 national-scale studies available and 28 other studies; interviewed 26 experts knowledgeable about the strengths and limitations of the studies; compared federal efforts to manage climate risks with leading practices for risk management and economic analysis; and obtained expert views.