Skip Navigation LinksUpdated-COVID-19-Testing-Guidance-6-16-21

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State of California—Health and Human Services Agency
California Department of Public Health

June 16, 2021

Public health officials, healthcare providers and laboratories

Updated Testing Guidance

​This Guidance is no longer in effect and is for historical purposes only. For current guidance see the COVID-19 Testing Guidance web page.


As of June 15, the state transitioned Beyond the Blueprint, where all industry and business sectors listed in the current Blueprint Activities and Business Tiers Chart may return to usual operations with no capacity limits or physical distancing requirements, with limited exceptions for mega events.

Furthermore, as we increase access to the COVID-19 vaccines, adapting testing guidance to focus testing on high-risk populations and individuals who have not been vaccinated allows us to further mitigate the spread of the virus by assisting with early detection and deploying both pharmaceutical and non-pharmaceutical preventative interventions when cases and outbreaks are identified.

As case rates decline, testing provides better insights into community prevalence and transmission as well as enabling us to perform genomic sequencing on respiratory samples from infected people to monitor the introduction of new variants into the community and the evolution of the virus. 

Testing is one layer in a multi-layered approach to COVID-19 prevention, in addition to other key measures such as vaccination, mask wearing, improved ventilation, physical distancing, and respiratory and hand hygiene.

Testing Guidance

Local jurisdictions may modify these guidelines to account for local conditions or patterns of transmission. Additionally, the California Department of Public Health (CDPH) will continue to reassess this guidance and adjust accordingly based on emerging evidence and U.S. Centers for Disease Control and Prevention (CDC) updates.

Diagnostic Testing for COVID-19

What is diagnostic testing?

Diagnostic testing for COVID-19 is used to test an individual for SARS-Cov-2 infection. SARS-Cov-2 is the virus that causes COVID-19.

What are the symptoms for COVID-19?

CDC's list of symptoms of COVID -19 includes fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea. Severe symptoms of COVID-19 include but are not limited to trouble breathing, persistent pain or pressure in the chest, new confusion, inability to wake or stay awake, pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone. Lists are available at the CDC symptoms and testing page

Who should have diagnostic testing?

Diagnostic testing should be considered for all individuals with symptoms or exposure to COVID-19.

What types of tests can be used for diagnostic testing?

Diagnostic testing may be performed using either molecular testing or antigen testing (see details of antigen and molecular testing below in the tests section). For symptomatic individuals who test negative on an initial antigen, repeat molecular testing should be performed within 1 day of the initial test and individuals should remain in isolation until confirmatory molecular test results are available.

Diagnostic Screening Testing for COVID 19

What is diagnostic screening testing?

Diagnostic screening testing is recurrent testing of asymptomatic individuals in certain high-risk non-healthcare and healthcare settings to detect COVID-19 early and stop transmission quickly.

Diagnostic screening testing can be used as a public health strategy to identify individuals who are infectious with SARS-CoV-2 but have no or very mild symptoms and to have them isolate so that they do not spread infection to others. The goal of screening testing is to detect cases early, and reduce the number of new infections or outbreaks in a given cohort. The CDC estimates that up to 60% of infections are transmitted while individuals are asymptomatic (and includes people who are pre-symptomatic and those who will never develop symptoms).

Who should have diagnostic screening testing?

Fully vaccinated individuals[1] do not need to undergo diagnostic screening testing in non-healthcare setting workplaces.

Non-healthcare workplace settings for which employee screening testing should be considered among non-vaccinated individuals, include:

  • Workplaces at increased risk of introduction of SARS-CoV-2; (e.g., workplaces where workers are in close and/or frequent contact with the public, such as public transit, restaurants, theaters or stadiums, amusement parks, transportation hubs, or workplaces in communities with substantial to high community transmission[2]).
  • High-density workplaces where there is a higher risk of SARS-CoV-2 transmission (e.g., indoor workplaces where physical distancing is difficult and workers might be in close contact, such as manufacturing or food processing plants, or workplaces that provide congregate housing for employees such as fishing vessels, offshore oil platforms, farmworker housing or wildland firefighter camps).
  • Staff in congregate residential settings (i.e homeless shelters, correctional facilities).
  • Workplaces in sectors with known higher risk of COVID-19 among workers, including but not limited to manufacturing, construction, retail, and food service workplaces.[3]

Employees (Healthcare Personnel – HCP) in Acute Health Care and Long-Term Care Facilities:

Diagnostic screening testing of asymptomatic employees should continue regardless of vaccination status, with the following exceptions:

  • Facilities may discontinue routine screening testing of asymptomatic staff who are fully vaccinated [1] where:
    •  >70% of residents and >70% staff are fully vaccinated in a Long-Term Care Facility (for LTCF staff) OR
    • >70% of staff are fully vaccinated in an Acute Health Care Facility.
  • Facilities may consider continuing routine screening testing for fully vaccinated staff with underlying immunocompromising conditions (e.g., organ transplantation, cancer treatment), which might impact the level of protection provided by COVID-19 vaccine. However, data on which immunocompromising conditions might affect response to the COVID-19 vaccine and the magnitude of risk are not available.
  • For more information on diagnostic screen testing in Long-Term Care Facilities and Acute Health Care Facilities, see SNF AFL 20-53.3.

Employers who conduct workplace screening testing should have a plan in place for tracking test results, conducting workplace contact tracing, and reporting results to public health departments and there are IT platforms available that can facilitate this for employers. Employers should also consult CDPH/ CDC guidance on workplace screening testing for additional cohort specific considerations. Testing is not a substitute for other COVID-19 prevention measures, such as vaccination, mask wearing, physical distancing, improved ventilation, hand hygiene and cleaning and disinfection.

What types of tests can be used for screening testing?

Antigen or molecular tests can be used for screening individuals who are asymptomatic but infected with COVID-19 and must either have Emergency Use Authorization by the U.S. Food and Drug Administration or be operating per the Laboratory Developed Test requirements by the U.S. Centers for Medicare and Medicaid Services. These tests need to be used at different frequencies, please see below for details.

How frequently should screening testing occur?

Screening testing frequency with molecular tests

The recommended minimum molecular test screening frequency is once weekly.  Molecular testing as a screening tool is most effective when turnaround times are short (<2 days). If the turnaround time is longer than 2 days, screening testing with PCR or NAAT is not as effective of a screening method.

Screening testing frequency with antigen tests

The recommended minimum antigen test screening frequency is twice weekly. Antigen tests conducted serially can be used to screen asymptomatic individuals for COVID-19 and reduce infections.

In some settings (e.g., K-12 schools), screening testing can be used at a cadence of every 2 weeks or less frequently, to understand whether the settings have higher or lower rates of COVID-19 rates than the community, to guide decisions about safety, and to inform LHDs.

Asymptomatic testing at a higher cadence (weekly or twice weekly) can be conducted to identify asymptomatic or pre-symptomatic cases early, in order to exclude cases that might otherwise contribute to transmission.

Screening testing is indicated for situations associated with higher risk (higher community transmission, individuals at higher risk of transmission, etc.).

Post- Exposure Testing for COVID-19 contacts

What is post exposure testing?

Post exposure testing for COVID-19 means testing people who are asymptomatic, but have been exposed to a confirmed or suspected case of COVID-19.

Who should receive post exposure testing?

Non-vaccinated Individuals

Fully vaccinated individuals

  • Most fully vaccinated people who are asymptomatic do not need to be tested following an exposure to someone with suspected or confirmed COVID-19, as their risk of infection is low.
  • Exceptions where testing (but not quarantine) is still recommended following an exposure to someone with suspected or confirmed COVID-19 include:
    • Fully vaccinated residents and employees of non-healthcare congregate settings
    • Fully vaccinated employees of high-density workplaces (e.g., food processing plants)
    • Fully vaccinated dormitory residents (or similar high-density housing settings) at educational institutions

Testing in these settings is still recommended because they may face high turnover of residents and/or a higher risk of transmission.

What types of tests can be used for post exposure testing?

Molecular or antigen tests can be used for post exposure testing.

When should post exposure testing occur?

In general, it is recommended to test immediately after being exposed to someone who has tested positive or has symptoms consistent with COVID-19. If the initial test is negative, and the exposed individual remains asymptomatic, testing is recommended again 5-7 days after exposure. If symptoms develop, diagnostic testing should be performed immediately.

Response Testing

What is response testing?

Response testing is repeat testing performed following an exposure that has occurred in high-risk residential congregate settings and high-risk/high-density workplaces, in accordance with CDC guidance. The goal of response testing is to identify asymptomatic infections in individuals in high risk settings and/or outbreaks to prevent further spread of COVID-19. Response testing should be initiated as soon as possible after an individual in a high risk setting has been identified to have COVID-19.

Who should be tested during response testing?

Response testing should occur for all individuals (residents and staff, regardless of vaccination status) in the facility as soon as possible after one (or more) individuals (resident or staff) with COVID-19 is identified in a facility. However, fully vaccinated staff are not required to quarantine or be excluded from work.

What tests can be used for response testing?

Either molecular or antigen testing can be used for response testing. It is recommended using the test with the fastest turn-around time that is available.

Response testing frequency with molecular tests

The recommended minimum response molecular test frequency is once weekly.  Molecular testing as a response testing tool is most effective when turnaround times are short (<2 days). If the turnaround time is longer than 2 days, response testing with molecular tests is not an effective screening method.

Response testing frequency with antigen tests

The recommended minimum antigen response test frequency is twice weekly. Antigen tests conducted serially can be used for response testing in asymptomatic individuals.

How long should response testing occur?

After completion of the first round of response testing, perform serial retesting at least weekly with molecular testing or a minimum of twice weekly with antigen testing of all residents and staff regardless of vaccination status who test negative upon the prior round of testing until no new cases are identified in sequential rounds of testing covering a 14 day period. Facilities should work with their local health department to help with outbreak management.

Response testing for outbreaks in workplaces.

The Cal/OSHA COVID-19 Prevention Emergency Temporary Standard requires once a week testing (antigen or molecular) of employees duing outbreaks of three or more persons and twice a week testing of employees for outbreaks of twenty or more persons.

Please note: exposed unvaccinated individual(s) should follow CDPH CDC guidelines for quarantine after exposure which can be found below in "Self-Isolation" or "Quarantine". Please refer to CDC guidelines for how to define an exposure to COVID-19.

Pre-Entry / Pre- Admission / Pre- Competition/ Pre- travel testing for COVID-19

What is Pre-entry Testing?

Pre-entry testing is testing performed prior to someone entering an event, competition, congregate setting, or other venue or business which can reduce the risk of spreading infection for people who are entering these settings.  Symptomatic individuals should not be allowed to enter.

Who should receive Pre-entry Testing?

Non-vaccinated Individuals

Individuals should have pre-entry testing performed if they have not been fully vaccinated [1] and will be taking part in activities that put them or others at higher risk for COVID-19 exposure. Pre-entry testing should be considered for those attending large indoor social or mass gatherings (such as large private events, live performance events, sporting events, theme parks, etc.), competing in high risk sports, or other events in crowded or poorly-ventilated settings.   

Vaccinated Individuals

Fully vaccinated individuals do not need to undergo pre-entry testing.

Should individuals who are traveling have pre-entry (pre-travel) testing? 

Individuals who are not fully vaccinated and must travel should follow pre-entry (pre –travel) testing recommendations in CDC travel guidance before and after travel. 

What types of tests can be used for Pre-Entry testing and when should they be performed?

CDPH recommends a point of care test (antigen or molecular) within 24 hours of entry in asymptomatic individuals. If point of care testing is not available, we recommend a molecular test of asymptomatic individuals within 72 hours of the event with results available before entry.

What can be used as proof of a negative pre-entry test?

The following are acceptable as proof of a negative COVID-19 test result:

  • A printed document from the test provider or laboratory, OR
  • An electronic test result displayed on a phone or other device from the test provider or laboratory.
    • The information should include person's name, type of test performed, and negative test result.

Should testing occur after the event, and if so when?

Since there is a possibility of exposure to individuals infected with COVID-19 in gatherings and congregate situations, consider testing 5-7 days after the event if an exposure is suspected and immediately if symptoms develop.

Are symptomatic individuals allowed to attend events if they have Pre-entry testing?

Symptomatic individuals should obtain diagnostic testing and should not be allowed to attend events or gatherings or be admitted to congregate settings; irrespective of their test results.

Testing after a diagnosis of COVID-19

There is no need to get tested after an initial positive confirmatory test to prove that an individual is no longer infectious and can end isolation. The end of isolation should be based on CDC and CDPH guidelines (currently 10 days) and is based on the time from initial diagnosis or symptom onset.  Individuals who had a positive viral test in the past 90 days and are now asymptomatic do not need to be retested as part of a screening testing program; testing should be considered again if it is more than 90 days after the date of onset of the prior infection, or if new symptoms occur. For individuals who develop new symptoms consistent with COVID-19 during the three months after the date of initial symptom onset, if an alternative etiology cannot be identified, then retesting for SARS COV-2 can be considered in consultation with infectious disease or infection control experts.


What types of tests are there?

Molecular testsMolecular tests amplify and then detect specific fragments of viral RNA. Depending on the test, different sequences of RNA may be targeted and amplified. Examples of this method include polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), and Nucleic Acid Amplification Test (NAAT). The real-time reverse transcriptase polymerase chain reaction (PCR) is the most commonly used molecular test and the most sensitive test for COVID-19. PCR is typically performed in a laboratory and results typically take one to three days. Point-of-care (POC) molecular tests are also available and can produce results in 15 minutes, but may have lower sensitivity (might not detect all active infections) compared with laboratory-based PCR tests.

Antigen tests: Antigen tests identify viral nucleocapsid protein fragments. They are typically performed at the point of care (POC) and produce results in approximately 15- 30 minutes. POC antigen tests have a slightly lower sensitivity (may not detect all active infections), but similar specificity (likelihood of a negative test for those not infected with SARS CoV-2) for detecting SARS-CoV-2 compared to PCR tests.

In symptomatic individuals a negative antigen test requires molecular test (PCR, LAMP, NAAT) confirmation and individuals should isolate until test results are available. If an individual is asymptomatic and tests positive with an antigen-based test, conduct confirmatory testing with a molecular test (PCR, LAMP, NAAT) and individuals should isolate until confirmatory test results are available.

These are the only types of tests that are recommended to diagnose COVID-19 infection. The FDA maintains a list of diagnostic tests for COVID-19 granted Emergency Use Authorization (EUA). No test is 100% accurate and test performance can vary depending on a number of test and patient factors as well as the underlying disease burden and pre-test probability in the individual being tested. 

What factors can impact the results of COVID-19 tests?

  • Viral Load: the amount of virus present in the testing site (e.g. nasal cavity) at a given time. 
  • Sensitivity: ability of a test to turn positive when an individual is in fact infected with SARS COV-2- the virus that causes COVID 19.
  • Specificity: ability of a test to be negative when an individual is not infected with SARS COV-2.
  • Stage of Infection: Sensitivity is also highly dependent on the stage of the infection.  In general, after exposure and infection the amount of detectable virus in the body remains low for the first few days of infection then rises exponentially and then decreases gradually over a period of time.
  • Immune response of the infected individual: A person's individual immune response, their personal health characteristics can impact the time course of their infection which all influence the level of viral load at any time point.
  • Different labs: Each lab's tests have their own sensitivity and specificity levels. Labs with a higher level of sensitivity can detect lower viral loads of COVID-19 that might not get picked up by a test with a lower sensitivity level.
  • Different tests:  Antigen tests and molecular tests have different abilities to detect viral loads thus impacting their sensitivities.
  • Sample collection and handling: Effective sample collection is dependent on different factors that can impact sample integrity including: collection technique and sealing of specimen, storage temperature, transportation, sample handling, and duration of time between sample collection and testing. 


Health insurance coverage

As provided by federal law[5], health plans and issuers must cover the cost of COVID-19 diagnostic tests without imposing any cost-sharing requirements (including deductibles, copayments, and coinsurance), prior authorization, or other medical management when the purpose of the testing is for individualized diagnosis or treatment of COVID-19. Further, health plans and issuers cannot require the presence of symptoms or a recent known or suspected exposure, or otherwise impose medical screening criteria on coverage of tests.

If you are having trouble accessing a COVID-19 test through your health plan or if you have any questions, please contact the Department of Managed Health Care Help Center at 1-888-466-2219 or visit the California Department of Managed Health Care (DMHC) Help Center web page.


As modifications are made to public health directives and more sectors of the economy open with adaptations, it is important that employers do not use testing to impermissibly discriminate against employees who have tested positive for COVID-19 (such as by preventing them from resuming work after they can do so in a manner consistent with public health and safety). Employees must complete their isolation period as per CDC and CDPH recommendations prior to returning to work. Further, proof of a negative test should not be required prior to returning to the workplace after documented COVID-19 infection. 

[1]   Individuals are considered fully vaccinated for COVID-19 two weeks or more after they have received the second dose in a 2-dose series (Pfizer-BioNTech or Moderna), or two weeks or more after they have received a single-dose vaccine (Johnson and Johnson [J&J]/Janssen ), or other COVID-19 vaccines authorized for use by the US Food and Drug Administration or the World Health Organization. See CDPH Recommendations for Fully Vaccinated People for updates.

[2] Per CDC levels of community transmission definition.: The indicators listed can be found by county on CDC's website with county view CDC COVID Data Tracker

[3] In California, these sectors have been identified in outbreak, surveillance and death data as settings with the potential for higher risk of COVID-19 exposure.

[4] Someone who was within six feet of an infected person for a cumulative total of 15 minutes or more over a 24-hour period.

[5] Frequently Asked Questions on Implementation of FFCRA and CARES Act. Centers for Medicare and Medicaid Services. February 26, 2021. FAQ Part 44 Cover Page (

Orignally Published on June 7, 2021