This report summarizes the aggressive measures ( 2, 3) that CDC, state and local health departments, multiple other federal agencies, and other partners are implementing to slow and try to contain transmission of COVID-19 in the United States. Fourteen cases have been diagnosed in the United States, and an additional 39 cases have occurred among repatriated persons from high-risk settings, for a current total of 53 cases within the United States. There have been 2,462 associated deaths worldwide no deaths have been reported in the United States. As of February 23, 2020, there were 76,936 reported cases in mainland China and 1,875 cases in locations outside mainland China ( 1). An outbreak of coronavirus disease 2019 (COVID-19) caused by the 2019 novel coronavirus (SARS-CoV-2) began in Wuhan, Hubei Province, China in December 2019, and has spread throughout China and to 31 other countries and territories, including the United States ( 1).