The U.S. Global Change Research Program (USGCRP) Climate and Health Assessment has been developed to enhance understanding and inform decisions about the growing threat of climate change to the health and well-being of residents of the United States. This scientific assessment is part of the ongoing efforts of USGCRP’s sustained National Climate Assessment (NCA) process and was called for under the President’s Climate Action Plan. USGCRP agencies identified human health impacts as a high-priority topic for scientific assessment. This assessment was developed by a team of more than 100 experts from 8 U.S. Federal agencies (including employees, contractors, and affiliates) to inform public health officials, urban and disaster response planners, decision makers, and other stakeholders within and outside of government who are interested in better understanding the risks climate change presents to human health. The USGCRP Climate and Health Assessment draws from a large body of scientific peer-reviewed research and other publicly available sources; all sources meet the standards of the Information Quality Act (IQA). The report was extensively reviewed by the public and experts, including a committee of the National Academies of Sciences, Engineering, and Medicine, the 13 Federal agencies of the U.S. Global Change Research Program, and the Federal Committee on Environment, Natural Resources, and Sustainability (CENRS).