One of the most critical aspects of transforming the nation's public safety answering points (PSAPs) from today's legacy 911 technology to Next Generation 911 (NG911) is adherence to a common set of standards. Development and adoption of international standards is key to achieving 911 interoperability across multiple local, regional, state, and national public safety jurisdictions, and beyond into the global emergency communications environment. Based on conceptual definitions dating from 2000, development began on NG911 standards in 2003 when the National Emergency Number Association (NENA) initiated technical requirements and definition work on core Internet Protocol (IP) functionality and architecture.Beyond the walls of the 911 PSAPs, the consistent observance of standards is essential in accomplishing seamless transmission of data from the caller to 911, and on to emergency responders. As PSAPs expand the forms of data they receive and transmit to each other, and as emergency responders migrate to a broadband network (e.g., FirstNet), it is essential that standards are established and consistently adopted.A variety of standards already exist, and many are actively under development. However, there is limited coordination across the broad NG911 community regarding what completed standards are available, what standards overlap, and what standards still need to be established. The National 911 Program, led by the United States (U.S.) Department of Transportation (USDOT), National Highway Traffic Safety Administration (NHTSA), has compiled this list of standards activities related to NG911. The standards development organizations (SDOs) mentioned herein were given the opportunity to vet the contents of this document, to assess the status of specific standards. This is a living document, and the National 911 Program will publish, monitor, support, and promote the activities of SDOs in establishing a comprehensive set of standards for NG911.