Testing for COVID-19 | COVID-19 | CDC

Nov 05, 2024

Viral tests look for a current infection with SARS-CoV-2, the virus that causes COVID-19, by testing specimens from your nose or mouth.

There are two main types of viral tests.

Nucleic acid amplification tests (NAATs), including PCR tests, are more likely to detect the virus than antigen tests. NAATs tests are the “gold standard” for COVID-19 tests.

Your sample will usually be taken by a healthcare provider and transported to a laboratory for testing and may take up to 3 days to receive results. Some NAATs may be performed at the point-of-care and provide results more quickly.

Antigen tests* are rapid tests that usually produce results in 15-30 minutes. Positive results are accurate and reliable. However, in general, antigen tests are less likely to detect the virus than NAAT tests, especially when symptoms are not present. Therefore, a single negative antigen test cannot rule out infection.

To be confident you do not have COVID-19, FDA recommends 2 negative antigen tests for individuals with symptoms or 3 antigen tests for those without symptoms, performed 48 hours apart. A single NAAT test can be used to confirm an antigen test result.

*Self-tests, or at-home tests, are antigen tests that can be taken anywhere without having to go to a specific testing site. Read self-test package inserts thoroughly and follow the instructions closely when performing the test.

You may choose a NAAT, including PCR, or antigen test. If you use an antigen test and your result is negative, repeat testing following FDA recommendations.

After a positive test result, you may continue to test positive for some time. Some tests, especially NAAT tests, may continue to show a positive result for up to 90 days.

Reinfections can occur within 90 days, which can make it hard to know if a positive test indicates a new infection.

Consider consulting a healthcare provider if you have any questions or concerns about your circumstances.

Buy self-tests (at-home tests) online or in pharmacies and retail stores. If you have health insurance, it may reimburse the cost of purchasing self-tests. Visit FDA's website for a list of authorized tests.

A positive COVID-19 test means the virus was detected and you have or recently had an infection.

A negative COVID-19 test means the test did not detect the virus, but this doesn't rule out that you could have an infection. If you used an antigen test, follow FDA recommendations for repeat testing.