The ongoing Ebola outbreak in the Democratic Republic of Congo (DRC), recently declared a ‘public health emergency of international concern’ by the WHO director general, is now second only to the West Africa outbreak of 2014-2015 in terms of number of cases and deaths. This new KFF explainer reviews the history of the outbreak in the DRC, which U.S. agencies are involved, how U.S. personnel are assisting, global response activities, and the role of vaccination in controlling the outbreak. The explainer also discusses how the U.S. government might change its approach and engagement in the DRC going forward, such as by providing additional funding or allowing U.S. government personnel to work directly in the outbreak zone