Currently, a few types of COVID-19 viral tests are available in the U.S. These tests aim to determine whether you currently are infected with the SARS-CoV-2 virus, the virus that causes COVID-19.
Below are answers to common questions about COVID-19 testing.
Who should get tested for COVID-19?
The CDC recommends you get tested for an active infection with the SARS-CoV-2 virus if you:
- Currently have COVID-19 symptoms.
- Have had close contact with someone who has tested positive for COVID-19. The CDC defines close contact as being within six feet of someone for 15 minutes or more during a 24-hour period. You should wait five days after being exposed before testing unless you develop symptoms before then. If you develop symptoms, test immediately.
- Are at higher risk for COVID-19 complications, or if infection rates are high in your area.
- Have engaged in activities within large groups of unmasked people, including mass transit (e.g., by plane, bus, or train) and large indoor gatherings.
What are the different types of COVID-19 viral tests available?
Two main types of COVID-19 diagnostic tests are available: molecular tests, also known as polymerase chain reaction (PCR) tests, and antigen tests. Molecular tests check for the presence of SARS-CoV-2 genetic material, while antigen tests check for the presence of a particular protein found on the SARS-CoV-2 virus.
Molecular tests are the most accurate, according to the U.S. Food and Drug Administration (FDA). They provide an accurate result about 95% of the time, but both false positive and false negative results are possible. Molecular tests use PCR or another type of nucleic acid amplification (NAAT) to detect genetic material from the SARS-CoV-2 virus.
Depending on the type of molecular test used, the testing sample may be collected using a nasal swab, throat swab, or swab from the area of the throat behind the nose. Usually, patients can get test results within one day, but sometimes it can take up to a week to get results if you’re in an area where labs have a backlog of tests to process, particularly during a surge of infections.
Most people now use at-home test kits to detect whether they have COVID-19. Antigen tests deliver fast results (typically within 15 to 30 minutes) by determining whether you have the active virus in your body. Most of these tests are performed by swabbing the nose or the area of the throat behind the nose. A list of all available types of at-home antigen tests can be found here.
Antigen tests are not as accurate as molecular tests, but when used properly, they’re accurate about 80% of the time when administered during the first week of infection. A positive test result is typically highly accurate, but false negatives make up most inaccurate results, according to the FDA. Thus, antigen testing may miss some current SARS-CoV-2 virus infection cases.
As of November 20, 2023, all U.S. residents are eligible to receive four free at-home COVID-19 tests, which are mailed to your home. You can order your free tests here. More free tests may be made available later. The CDC has the latest guidance on self-testing. Make sure you follow the instructions on the test, follow each step in order, and wait the recommended amount of time before checking your results.
What if I have expired tests?
If you have an expired at-home COVID-19 test, check to see whether the expiration date has been extended before throwing it out. This video provides more information on expired tests. You can check on any expiration date extensions to determine whether the test is still viable
at this FDA link. If the test truly has expired, you should not use it and throw it away.
What if I have symptoms, but my at-home test result is negative?
Just because you test negative does not mean you do not have a SARS- CoV-2 infection. Sometimes it takes an extra day or two for an antigen test result to be positive. You should wear a mask to protect other people from your illness, then test again 48 hours after a negative result.
Can I get tested for COVID-19 by a healthcare provider?
Contact your state health department to see where COVID-19 testing sites are located in your area. You also can contact your local pharmacy or urgent care clinic, as many perform on-site COVID-19 testing.