How Common Are False Positive COVID-19 Tests? Experts Explain. Home testing is convenient and reliable—when done correctly.

What Is a False Positive COVID-19 Test? Everything to Know About At-Home Testing You could be swabbing your nose incorrectly. Jake Smith Prevention

But how accurate are antigen tests? False positive COVID-19 tests—when your result is positive, but you aren’t actually infected with the SARS-CoV-2 virus—are a real, if unlikely, possibility, especially if you don’t perform your at-home test correctly.

Don’t dispose of your stash of at-home COVID-19 tests, though: “[False positives] are not very common at all,” explains Gigi Gronvall, Ph.D., a senior scholar at the Johns Hopkins Center for Health Security, where she has led efforts to track the development of COVID-19 testing. “It happens, but it is extremely rare.”

Rapid tests are even more trustworthy now, with so many people infected with the novel coronavirus, says Geoffrey Baird, M.D., Ph.D., professor and chair of the Department of Laboratory Medicine and Pathology at the University of Washington School of Medicine. Before you can assume your positive COVID-19 test is a fluke, you need to understand why false positives exist in the first place. ...