Important update: Healthcare facilities
CDC has updated select ways to operate healthcare systems effectively in response to COVID-19 vaccination. Learn more
UPDATE
Given new evidence on the B.1.617.2 (Delta) variant, CDC has updated the guidance for fully vaccinated people. CDC recommends universal indoor masking for all teachers, staff, students, and visitors to K-12 schools, regardless of vaccination status. Children should return to full-time in-person learning in the fall with layered prevention strategies in place.
UPDATE
The White House announced that vaccines will be required for international travelers coming into the United States, with an effective date of November 8, 2021. For purposes of entry into the United States, vaccines accepted will include FDA approved or authorized and WHO Emergency Use Listing vaccines. More information is available here.

COVID-19 Testing: What You Need to Know

COVID-19 Testing: What You Need to Know
Updated May 2, 2024
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COVID-19 testing can help you know if you have COVID-19 so you can decide what to do next, like getting treatment to reduce your risk of severe illness and taking steps to lower your chances of spreading the virus to others.

When you get tested:
  • Choose the right type of test for your circumstance
  • For antigen tests, follow test directions as recommended by FDA and the test manufacturer

If you do not, your results may be less likely to correctly indicate whether you have COVID-19 or not.

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Types of Tests

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:

  • Polymerase chain reaction (PCR) tests
  • Antigen tests

PCR Tests

healthcare provider using nasal swab for COVID test sample on patient

PCR tests are the “gold standard” for COVID-19 tests. They are a type of nucleic acid amplification test (NAAT), which are more likely to detect the virus than antigen tests. Your sample will usually be taken by a healthcare provider and transported to a laboratory for testing. It may take up to 3 days to receive results.

Antigen Tests

rapid antigen tests

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 PCR 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 PCR 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.

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Choosing a COVID-19 Test

I want to get tested and:

I have not had COVID-19 or I have not had a positive test within the past 90 days.

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

I tested positive for COVID-19 in the last 90 days.
My first positive test result was within:

30 days or less

I have symptoms
Use an antigen test. Repeat negative tests following FDA recommendations.

I do not have symptoms
Testing is not recommended to detect a new infection.

My first positive test result was within:

31-90 days

I have symptoms
Use an antigen test. Repeat negative tests following FDA recommendations.

I do not have symptoms
Use an antigen test. Repeat negative tests following FDA recommendations.

After a positive test result, you may continue to test positive for some time. Some tests, especially PCR 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.

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Getting a COVID-19 Test

Buy self-tests (at-home tests)

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.

Go to a testing location

  • Visit a community-based testing location, such as a pharmacy or health center near you. These locations may offer PCR or antigen tests, and provide low- or no-cost testing for everyone, including people without insurance. Free PCR or antigen tests may also be available through your local health department.
  • Talk to a doctor or healthcare provider about other testing options that may be available to you.
  • If you are a person with a disability, the Disability Information and Access Line can help you access a test or find a test location.
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Interpreting Your Results

If Your COVID-19 Test Is

Positive

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

  • Take steps to prevent spreading COVID-19.
  • Monitor your symptoms. If you have any emergency warning signs, seek emergency care immediately.
  • Seek health care right away for treatment if you have risk factors for severe illness. Treatment may be an option to make your symptoms less severe and shorten the time you are sick. Treatment needs to be started within a few days of when your symptoms begin.
If Your COVID-19 Test Is

Negative

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.

  • If you have symptoms:
    • You may have COVID-19 but tested before the virus was detectable.
    • You may have another viral infection or illness.
    • Take actions to help protect yourself and others from health risks caused by respiratory viruses.
    • Contact a healthcare provider if you have any questions about your test result.

Testing Resources for Healthcare Professionals: Healthcare Workers | Labs

Archived Content

Search for and find historical COVID-19 pages and files. Please note the content on these pages and files is no longer being updated and may be out of date.

  • Visit archive.cdc.gov for a historical snapshot of the COVID-19 website, capturing the end of the Federal Public Health Emergency on June 28, 2023.
  • Visit the dynamic COVID-19 collection to search the COVID-19 website as far back as July 30, 2021.