On January 12, 2021, the Centers for Disease Control and Prevention (CDC) issued an Order (the CDC Order), which will require all air passengers travelling to the United States from a foreign country to present either of the following to the airline or aircraft operator (i.e., an individual or organization causing or authorizing the operation of an aircraft) before boarding the flight: (a) a negative result for a COVID-19 test, or (b) sufficient documentation of having recovered from COVID-19. Air passengers will also be required to confirm that the information they present is true by means of an attestation. The CDC Order was formally published in the Federal Register on January 21, 2021, and will become effective as of 12:01am EST on January 26, 2021. 
On January 21, 2021, President Joe Biden also issued the Executive Order on Promoting COVID-19 Safety in Domestic and International Travel (the Executive Order). It requires relevant Federal Government Agencies to assess the implementation of the CDC Order (within 14 days of the Executive Order) and take any appropriate regulatory action. Among other things, the Executive Order also requires relevant Federal Government Agencies to consider additional measures such as mandatory quarantine/isolation, the implementation of COVID-19 safety measures at land and sea ports of entry, and the possible use of International Certificates of Vaccination or Prophylaxis (ICVPs) for COVID-19. It also immediately imposes a federal mask requirement on airports, commercial aircraft, trains, public maritime vessels (including ferries), intercity bus services, and all forms of public transportation.