This publication is the result of an ongoing collaborative effort involving industry, academia, and government. The National Institute of Standards and Technology (NIST) launched the project by convening private- and public-sector organizations and individuals in 2013. Published in 2014 and revised during 2017 and 2018, this Framework for Improving Critical Infrastructure Cybersecurity has relied upon eight public workshops, multiple Requests for Comment or Information, and thousands of direct interactions with stakeholders from across all sectors of the United States along with many sectors from around the world.