Do You Need to Retest After a Positive COVID-19 Result?

The CDC provides guidelines on what to do

If you test positive for COVID-19 and isolate for at least 5 days, you don't need to get re-tested if you have fully recovered.

This article explains why the Centers for Disease Control (CDC) does not recommend re-testing for those who have recovered. It also explains how long you may be contagious after testing positive for COVID-19, how long you can continue to test positive, and when to stop isolation if you are symptom-free.

Woman taking at-home Covid test

AzmanL / Getty Images

What Do I Do If I Test Positive for COVID-19?

If you test positive for COVID-19, the CDC recommends you stay home and isolate for at least five days (day 0 through day 5).

  • Day 0 is the day you first started to feel symptoms. If you never felt symptoms, day 0 is the day you took your positive COVID-19 test.
  • Day 1 is the first full day after you started feeling symptoms or took the test. This is your first full day of isolation.
  • Day 5 is the last day of isolation if you never had symptoms or your mild symptoms are improving.
  • Day 6 is the first day you can stop isolating. You should continue to wear a well-fitting mask around others.
  • Day 11 is the first day you can stop wearing a mask around others.

If you develop symptoms within 10 days of testing positive, restart your isolation at day 0.

Do I Need to Test After I Have COVID-19?

There's no test required to leave isolation. But you can use rapid antigen tests to see if you can stop wearing your mask sooner than day 11.

The CDC recommends that you only take the antigen test on day 6 if you have been fever-free for 24 hours (without the use of fever-reducing medication) and your other symptoms have gotten better.

If your antigen test results are positive, you should wait at least 48 hours before taking another test. You should continue taking antigen tests 48 hours apart until you get two negative tests in a row. Only then should you remove your mask.

Repeat testing after recovery from COVID-19 is not required after 10 days of isolation.

What If I'm Immunocompromised or Very Sick?

The CDC's guidelines do not apply to moderately or severely ill people with COVID-19 or people with weakened immune systems.

Immunocompromised people should always isolate for at least 10 days. People who are severely sick may need to isolate for up to 20 days.

If a person does not have access to repeat COVID-19 testing after five days in isolation or does not want to retest, the CDC recommends they take precautions until day 10.

At-Home COVID Testing

If you have mild to moderate symptoms, you might do COVID-19 testing and take care of yourself at home. Starting December 15, 2022, every household can order four free at-home COVID tests by going to COVIDTests.gov.

How Long Will I Test Positive After Having COVID-19?

With PCR tests people can continue to test positive for COVID-19 even if they're no longer symptomatic or contagious. They may keep testing positive for COVID-19 weeks or even months after they were sick.

Research has shown that with PCR tests, viral particles can be detected in most people as early as six days before COVID-19 symptoms start and continue to show up until two weeks later.

While viral RNA can still be detected on a test, scientists have not been able to grow the live virus from collected specimens nine days after symptoms started.

That means that even though a person can continue to test positive for COVID-19, they are no longer contagious eight days after they started having symptoms.

How Can Someone Test Positive for COVID-19 and Not Be Infectious?

The best COVID-19 tests are the nucleic acid reverse transcriptase-polymerase chain reaction (RT-PCR) tests. These tests make copies of viral genetic material in respiratory samples. The tests can take a single copy of viral RNA and amplify it to show a positive result.

These tests are very good at detecting small amounts of viral material. However, the viral fragments do not indicate a live virus is present.

Just because the material is detected does not mean that the viral fragments will cause symptoms or be passed to others. The viral fragments can be detected for up to three months.

If I Keep Testing Positive for COVID-19 Will I Become Contagious Again?

Repeat COVID infection makes the question of retesting a little more complicated.

People who have recovered from COVID-19 get protective antibodies that help prevent the virus from replicating and infecting new cells. However, scientists do not fully understand the effectiveness of antibody protection or how long it lasts.

Some studies have suggested that neutralizing antibodies are present for at least six months, which means the risk of reinfection is low but not impossible.

Research has also shown that COVID-19 reinfection is more likely in unvaccinated people. However, breakthrough COVID-19 infections can also happen to fully vaccinated people. 

Should I Retest If I've Recovered From COVID-19 But Have Symptoms Again?

According to the CDC guidelines, testing is not recommended as part of a contact tracing program or new exposures within three months of a positive COVID-19 test. During that time, a positive test result could be from the previous infection rather than a new infection.

However, the recommendation is different if a person experiences symptoms of COVID-19 within that three months. In that case, repeat testing is recommended.

If the test is positive, a person should restart the five-day isolation period and follow the recommended guidelines.

Can My Employer Require a Negative COVID-19 Test Before I Can Return to Work?

Several workplaces have implemented COVID-19 screening to help prevent the spread of the virus. The CDC advises employers on how to use testing strategies in non-healthcare settings.

However, the CDC does not recommend requiring a negative COVID-19 test result before allowing employees to return to work.

According to the Americans with Disabilities Act (ADA), employers who put mandatory COVID-19 testing of employees in place must make sure that the testing is job-related and consistent with a business necessity. The purpose of the program should be to identify current infections.

What Does the CDC Recommend Employers Do About COVID-19 Testing?

Based on the evidence of continued positive results for months after illness, the CDC recommends a time-based and symptom-based strategy for determining when an employee can return to work.

This strategy means that people should follow the CDC guidelines for five days of isolation and should not go back to work until symptoms improve or resolve.

According to the ADA, employers can require a healthcare provider’s note certifying fitness for duty after a COVID-19 infection. However, health organizations have stressed that the requirement could be burdensome because many providers are too busy to provide fitness for duty documentation.

The CDC recommends that employers consider not requiring a provider’s note for employees to return to work. However, some employers do.

CDC Guidelines for Employers

Employers who have put regular COVID-19 screenings in place will likely require repeat testing when employees come back to work. However, the ADA requires that employers follow current CDC guidelines for repeat testing and returning to work.

If I Continue to Test Positive, Does That Mean I Have Long COVID?

The World Health Organization (WHO) has developed a clinical definition for post-COVID syndrome—also known as long COVID. The chronic condition has been seen in people:

  • With a history of probable or confirmed SARS-CoV-2 infection 
  • Who continue to have symptoms three months after the onset of initial symptoms or test positive for COVID-19
  • Who have symptoms lasting for at least two months 
  • Whose symptoms cannot be explained by another diagnosis 

The symptoms long COVID are being added to an ever-growing list, but some of the most commonly reported symptoms are:

  • Fatigue
  • Shortness of breath
  • Cough
  • Chest pain
  • Joint or muscle pain
  • Headache
  • Cognitive dysfunction or difficulty concentrating
  • Sleep problems
  • Mood changes
  • Changes in smell or taste
  • Changes in a person's menstrual cycle

Post-COVID-19 conditions like long COVID are clinical diagnoses. That means we do not have a specific test for them yet.

We do know that long COVID is not more common in people who continue to test positive for the virus.

A lot of what we know about long COVID came from the CDC when they looked at a small group of people to try to understand long COVID risk factors.

We're still learning about long COVID, including what makes a person more likely to get it. That said, there are a few factors that might make long COVID more likely:

  • People hospitalized for the illness
  • Females
  • Black people
  • People aged 40 and older
  • People with preexisting health conditions

Summary

The CDC does not recommend repeat COVID-19 testing for people who have recovered from the illness. Many people continue to test positive for months and are not contagious.

Instead, the CDC says people with mild illness can start using antigen tests on day 6 to determine if they should continue wearing a mask until day 11.

The CDC does not recommend repeat testing for returning to work. Instead, workplaces should follow the CDC guidelines and use a time-based and symptom-based strategy for letting employees come back to work.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

Frequently Asked Questions

  • Is it possible to be infected with two different COVID-19 variants at the same time?

    It's not common, but there have been case reports of people who have been diagnosed with two COVID variants at the same time.

  • Do I need to retest a positive COVID test for travel?

    You'll need to check the testing requirements for your destination. You may need to show a negative COVID-19 test to enter a country or come back to the country you traveled from. If you test positive for COVID-19 while you are traveling, you will need to follow the guidelines for isolation, testing, and treatment where you are.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Christine Zink, MD
Dr. Christine Zink, MD, is a board-certified emergency medicine with expertise in the wilderness and global medicine. She completed her medical training at Weill Cornell Medical College and residency in emergency medicine at New York-Presbyterian Hospital. She utilizes 15-years of clinical experience in her medical writing.