The rapid spread of the COVID-19 pandemic in the U.S. revealed the urgency for digital contact tracing tools to supplement traditional contact tracing efforts. PHII led a national forum of experts in public health and private sector technology to produce key guidance that supports public health in deciding the appropriate technology that would enhance their traditional contact tracing efforts. Now, public health authorities in more than 50 countries, states and regions have developed exposure notification apps to track and fight COVID-19.