The Centers for Disease Control and Prevention updated its guidance for travel suggesting Americans flying domestically should get tested for COVID-19 “as close to the time of departure as possible.”

On Tuesday, the Biden administration announced Tuesday that all Americans can now receive a third round of free COVID-19 tests in the mail.

Here is how you can order a free COVID-19 test:

Visit COVIDTests.gov or call 1-800-232-0233.

Each household is eligible for up to eight additional tests.

The CDC’s guidance also suggests getting tested after travel if your trip involved situations with a greater risk of exposure such as being in crowded places while not wearing a well-fitting mask or respirator.

Currently, masks are not required on domestic flights and most public transit systems after a federal judge ruled against the CDC striking down the mask mandate on public transit.

Although not mandated, the CDC continues to recommend the use of masks while using indoor public transit, including planes, buses and trains.