Learn about COVID-19 testing

Last updated July 20, 2022.

Available languages: Español

Stock image: PCR test box

This webpage has information about different types of COVID-19 tests, what test results mean, and what to do after you get your test result. 

Looking for a test? Visit our Find a COVID-19 test webpage.


Why get tested

It is important to layer strategies to protect ourselves, loved ones, and community from COVID-19. In Colorado, it’s easy to get a free, fast, and safe COVID-19 test. Through ongoing testing, Coloradans can help slow the spread of COVID-19.


Who can get a test

Anyone who wants a test should get one. 

If you have symptoms of COVID-19, which can feel like a cold, you should get tested as soon as possible, even if you’ve received all recommended doses of the COVID-19 vaccine. Follow instructions on how to isolate until you feel better.

If you have been around someone who has COVID-19, you should get tested five days after you were exposed, even if you have received all recommended doses of the COVID-19 vaccine. If you aren’t up to date with your vaccines and you were exposed to someone with COVID-19, you should also follow instructions on how to quarantine. (Some people may need to quarantine even if they are up to date with vaccines depending on where they live or work.) 

You may need to test before and/or after traveling. Check CDC’s travel guidance for more information.


What to do if you test positive

If you test positive for COVID-19, follow instructions on how to isolate

You may be able to get treatment to help you recover from COVID-19. This can help keep you from getting seriously sick and keep you out of the hospital. Learn more about treatment for COVID-19.

If you used an at-home test, report your positive result using our web portal.

If you have Exposure Notifications enabled on your phone, report your positive result in the service to anonymously alert your recent close contacts that they were exposed.

Federal law requires up to two weeks paid leave for those who work for employers with fewer than 500 employees (though some employers with 50 or fewer employees may be exempt). The Colorado Health Emergency Leave with Pay Rules (“Colorado HELP Rules”) adds coverage for workers as well.

There are many resources available to help you if you need to isolate or quarantine, including personal financial help and help with getting food.


Types of COVID-19 tests 

There are many types of COVID-19 tests. 

Some tests tell you if you are currently infected with the virus that causes COVID-19. These tests are often called viral or diagnostic tests. Other tests tell you if you may have been infected in the past. These tests are often called serologic or antibody tests. They use a blood sample to test for antibodies or cells from your immune system.

Some tests must be sent to a lab to get results. Other tests can be taken at a local clinic, pharmacy, or at home without being sent to a lab.

Types of viral tests 

Molecular-based/PCR testing

  • A molecular amplification test looks for genetic material from the COVID-19 virus. PCR tests are a type of molecular test. A lab-based PCR test is one of the most reliable and accurate ways to test for COVID-19. There are other molecular tests that are not called PCR. 
  • These tests may also be called Nucleic Acid Amplification Tests, or NAATs, and are often performed in a laboratory. 
  • Tests performed in a lab are called lab-based tests. However, some of these tests can be performed at the point of care (a clinic, pharmacy, or at home).

Antigen/rapid testing

Types of serologic tests

Antibody testing

  • An antibody test is a blood test that looks for antibodies. It can detect the body’s immune response to the infection caused by the virus, rather than detecting the virus itself. 
  • While these tests can detect previous exposure to COVID-19, they can’t tell if someone is currently infected and able to spread the virus to others. It is not recommended to use these tests to find out if you currently have COVID-19. 
  • More information about serological testing can be found in CDC’s Interim Guidelines for COVID-19 Antibody Testing.

Other immune testing

  • Other immune tests, such as t cell tests, use blood samples to look for immune response cells in your blood. These tests can detect the body’s immune response to the infection caused by the virus, rather than detecting the virus itself. 

Taking a rapid test

  • Get an FDA-authorized test. This is the best way to make sure that your test works well and is accurate. 
  • Double check the expiration date of your test. The FDA has extended expiration dates of many tests. If your test seems to be expired, it may actually still be usable. Check the expiration date on the box against our list of extended expiration dates.
  • Make sure you follow the instructions for storage and use that came with your test. 
  • If you live or work in a high risk setting, such as a residential care facility, or a correctional facility, refer to the guidance for your specific setting when interpreting test results.


What to do once you have your rapid test result

Some people who take a rapid test may wish to take a lab-based test as well to confirm their results. Rapid tests may rarely result in false negatives or false positives. Taking a more sensitive test can help you confirm that you do or do not have COVID-19.

Consider whether or not you have symptoms, whether you’ve recently had close contact with someone who has COVID-19, and the local COVID-19 community level when deciding whether or not to retest. 

Use the chart below to find out if retesting is recommended for you. If you need to retest, you should get a PCR test within 48 hours of your rapid test.

Do I need another test?


COVID-19 risk level

Rapid Antigen Test Result 
(e.g., BinaxNow, iHealth, etc.)

Lower risk

At least one risk factor

  • Symptoms
  • Recent exposure to COVID-19
  • Local outbreak
  • Medium or high community level


You may have COVID-19 even if you don’t have symptoms, but it is less likely if you had no recent exposure and community levels are low. If your rapid test came back positive and you are at low risk, we recommend confirming your test result with a more sensitive PCR test. 

Find a testing site near you

If your PCR test is POSITIVE, you have COVID-19 and need to begin isolation
If your PCR test is NEGATIVE, you do not have COVID-19 and do need to isolate.

Getting another test is not necessary. This positive result means you have COVID-19. You should isolate yourself away from others.


Getting another test is not necessary. You likely do not have COVID-19.

If you have symptoms, it is possible that you had a false negative on your rapid test and have COVID-19. We recommend getting a lab-based test to confirm your rapid test results.

Find a testing site near you

If your PCR test is POSITIVE, begin isolation.
If your PCR test is NEGATIVE, you do not need to isolate. If you are sick with another illness, we recommend staying home until you feel better.