Rapid antigen tests aren't perfect. False positives — meaning your test is positive but you're not actually infected — are possible with antigen tests, although less likely if you're symptomatic. "What's more concerning than a false positive, though, is a false negative.

Can COVID-19 antigen tests be false positive?

Despite the high specificity of antigen tests, false positive results will occur, especially when used in communities where the prevalence of infection is low – a circumstance that is true for all in vitro diagnostic tests.

What are consequences of a false negative COVID-19 test?

Risks to a patient of a false negative test result include: delayed or lack of supportive treatment, lack of monitoring of infected individuals and their household or other close contacts for symptoms resulting in increased risk of spread of COVID-19 within the community, or other unintended adverse events.