I flew United back to the US from Mexico on Tuesday. I was scheduled to take an antigen test at a hospital there but a few weeks prior to the return United sent a link for Abbott Lab BinaxNOW rapid test which we took. Self-administered with a
proctor, results are then uploaded the night before the return flight to United. Buy the kits, bring them with you, take the test the required days/hours before the flight.
From Abbott's website:
BinaxNOW is a rapid test that detects COVID-19 antigens (the proteins that make up the virus) to help identify someone is currently infected. It is easy-to-use, provides fast results and can help healthcare professionals quickly identify infectious people so they can take measures to help prevent the spread of the disease to others.
Everything needed to perform the BinaxNOW antigen test is included in a credit-card-sized kit, which lets authorized healthcare providers (such as a school nurse) test quickly and easily.
The BinaxNOW test has been authorized by the U.S. Food and Drug Administration through its Emergency Use Authorization process and is intended to identify antigen from SARS-CoV-2 in a nasal swab. For complete information on the BinaxNOW test, visit
https://www.fda.gov/media/141570/download.