The Visa Waiver Program allows nationals from the 38 VWP countries to travel to the United States for tourism or business for up to 90 days without a visa. To help prevent terrorists and others who present a threat from travelling to the United States, DHS requires VWP countries to, among other things, enter into information-sharing agreements with the United States. In addition, U.S. law requires DHS to evaluate, at least once every 2 years, the effect of each VWP country's participation on U.S. law enforcement, security, and immigration enforcement interests; determine whether the country should continue in the program; and report on its determination to Congress. GAO was asked to review the VWP. In this report, GAO examines the extent to which VWP countries have implemented the required agreements. GAO also examines the extent to which DHS evaluated VWP countries and reported to Congress as required. GAO reviewed documents related to the VWP, including a sample of DHS reports. In addition, GAO interviewed U.S. officials in Washington, D.C., and U.S. and foreign officials in four VWP countries selected on the basis of factors such as high estimated numbers of foreign terrorist fighters. This is a public version of a classified report GAO issued in January 2016.