The CDC has recently issued a new order, effective January 26, 2021, that requires all travelers arriving to the US from a foreign country to get tested no more than 3 days before their flight departs and to provide proof of the negative result or documentation of having recovered from COVID-19 to the airline before boarding the flight.

The CDC has provided testing information viewable on the CDC website.

The FDA testing basics site is the best resource to help you answer testing questions from students and other potential travelers.