This page is part of the FAQs on Testing for SARS-CoV-2 and provides answers to frequently asked questions related to uses for different types of COVID-19 tests and the settings in which they can be used.
A: The FDA has issued a number of Emergency Use Authorizations (EUAs) for COVID-19 tests. All COVID-19 tests that are authorized under an EUA can be found on the In Vitro Diagnostics EUA page.
Each EUA includes the settings in which the test is authorized. Facilities performing COVID-19 testing must be certified as a laboratory under the Clinical Laboratory Improvement Amendments, or CLIA, which is administered by CMS. Laboratories may perform tests for which they meet the qualifications of the authorized settings noted in the EUA. Laboratories authorized to use such tests are subject to various conditions that can be found in the EUA.
As discussed in the Guidance for Industry and Other Stakeholders: Emergency Use Authorization of Medical Products and Related Authorities, when the FDA issues an EUA for a test, it can indicate whether the test can be performed at the point of care. The FDA must make certain determinations for tests to be deemed to be CLIA waived tests. Generally, for the duration of the emergency declaration, such authorized tests can be performed in a patient care setting that is qualified to have the test performed there as a result of operating under a CLIA Certificate of Waiver, Certificate of Compliance, or Certificate of Accreditation.
We note that the term point of care in the EUAs may include settings such as hospitals, physician offices, urgent care, outreach clinics, pharmacies, and temporary patient care settings that have appropriately trained personnel to perform the test and are operating under a CLIA Certificate of Waiver or Certificate of Compliance. Tests authorized for use at the point of care generally are not authorized for home specimen collection or at home testing unless otherwise specified.
For ease of reference, the settings authorized in the EUAs are also noted in the EUA tables on the In Vitro Diagnostics EUA page.
- Tests that are noted with an "H" in the Authorized Settings are limited to use in laboratories certified under CLIA that meet requirements to perform high-complexity tests.
- Tests that are noted with an "H" and "M" in the Authorized Settings may be performed in laboratories certified under CLIA to perform high complexity and/or moderate complexity tests.
- Tests that are noted with a "W" in the Authorized Settings are deemed to be CLIA-waived for use in patient care settings operating under a CLIA Certificate of Waiver.
- Tests noted with an "H," "M," and "W may be used in laboratories certified under CLIA that meet requirements to perform high complexity and/or moderate complexity tests and in patient care settings operating under a CLIA Certificate of Waiver.
A number of EUAs have been issued for tests that must be performed in a laboratory, but for which the samples can be collected at home and sent to the laboratory. Such tests include “Home Collection” in the Attributes column in the EUA tables. The FDA has also issued a number of EUAs for COVID-19 tests that may be used at home, which is stated in the EUA. The Authorized Setting for such tests is noted as “Home” in the EUA tables. Tests authorized for home use can generally also be used for self-testing in settings outside of the home, such as offices or schools.
Additionally, as discussed in Section IV.C of the Policy for Coronavirus Disease-2019 Tests, reissued on November 15, 2021, FDA has policies regarding the distribution and offering of certain tests for clinical use prior to or without an EUA. Unless and until an EUA is issued that authorizes additional testing environments for a specific test, under the Clinical Laboratory Improvement Amendments (CLIA), section 353 of the Public Health Service Act (42 USC 263a), use of that test is limited to laboratories that are certified under CLIA, and meet the requirements to perform tests of high-complexity, and at the point-of-care (POC) when covered by such a laboratory’s CLIA certificate.
The policies regarding offering a COVID-19 tests prior to an EUA have never applied to at-home tests or tests with home specimen collection, or any testing outside of a high-complexity CLIA-certified laboratory.
A: Some COVID-19 tests require a prescription and others do not. COVID-19 tests authorized for use without a prescription include the attribute "DTC" (for direct-to-consumer home collection tests) or "OTC" (for over-the-counter at-home tests) in the EUA tables on the In Vitro Diagnostics EUA page.
Each EUA-authorized test has a Letter of Authorization (LOA) and Instructions for Use (or an EUA Summary for tests developed by a laboratory) available on the In Vitro Diagnostics EUA page. These documents include FDA requirements regarding ordering the test. For example, there is a condition in the LOAs that the manufacturer comply with 21 CFR 809.10(a)(4), which states that, among other things, the label of an in vitro diagnostic product shall include certain references to: (1) "Rx," (2) a statement regarding the restriction to sale by or on the order of a physician, dentist, veterinarian or (3) with the descriptive designation of any other practitioner licensed by the law of the State in which the practitioner practices to use or order the use of the device. As such, State licensing laws may need to be consulted to determine exactly who can use or order an EUA-authorized COVID-19 test.
Tests offered prior to or without an EUA, as described in the Policy for Coronavirus Disease-2019 Tests, are limited, under CLIA, to use in laboratories certified under CLIA that meet requirements to perform high-complexity tests. Under CLIA regulatory requirements, such laboratories must have a written or electronic request for patient testing from an individual authorized under State law to order tests and/or receive test results. See 42 CFR 493.1241(a); 42 CFR 493.2. State laws should be consulted to see exactly who can order a COVID-19 test.
A: Surveillance for COVID-19 includes ongoing systematic activities, including collection, analysis, and interpretation of health-related data, essential to planning, implementing, and evaluating public health practice. It is generally used to monitor for an occurrence, such as an infectious disease outbreak, in a population or community, or to characterize the occurrence once detected, such as looking at the incidence and prevalence of the occurrence. Surveillance testing is primarily used to gain information at a population level, rather than an individual level. Surveillance testing may be random sampling of a certain percentage of a specific population to monitor for increasing or decreasing prevalence and determining the population effect from community interventions such as social distancing. FDA generally does not regulate surveillance testing. An example of surveillance testing is a testing plan developed by a State Public Health Department to randomly select and sample 1% of all individuals in a city on a rolling basis to determine local infection rates and trends.
Generally, if at any time a patient-specific result is to be reported by a facility, it must first obtain a CLIA certificate appropriate to the test system the laboratory intends to use and meet all requirements to perform testing. For more information on CMS and CLIA policies, including new policies during the COVID-19 public health emergency, see:
- Research Testing and Clinical Laboratory Improvement Amendments of 1988 (CLIA) Regulations (PDF)
- Frequently Asked Questions: SARS-CoV-2 Surveillance Testing (PDF)
- CLIA University Lab Testing (PDF)
Screening for COVID-19 is looking for occurrence at the individual level even if there is no individual reason to suspect infection such as a known exposure. This includes broad screening of asymptomatic individuals without known exposure with the intent of making individual decisions based on the test results. Screening tests are intended to identify infected individuals prior to development of symptoms or those infected individuals without signs or symptoms who may be contagious, so that measures can be taken to prevent those individuals from infecting others. FDA regulates screening tests as in vitro diagnostic devices and has provided recommendations and information regarding EUA requests for COVID-19 screening tests in the EUA templates referenced in the Policy for Coronavirus Disease-2019 Tests. Examples of screening include testing plans developed by a workplace to test all employees returning to the workplace regardless of exposure or signs and symptoms and testing plans developed by a school to test all students and faculty returning to the school regardless of exposure or signs and symptoms, with the intent of using those results to determine who may return or what protective measures to take on an individual basis.
Diagnostic testing for COVID-19 is also looking for occurrence at the individual level but is performed when there is a particular reason to suspect that an individual may be infected. Diagnostic tests are intended to diagnose an infection in patients suspected of COVID-19 by their healthcare provider such as in symptomatic individuals, individuals who have had a recent exposure, individuals who are in a high-risk group such as healthcare providers with known exposure, or testing to determine resolution of infection. Diagnostic tests may also be appropriate in areas of high community spread, at the discretion of the ordering healthcare provider. FDA regulates diagnostic tests as in vitro diagnostic devices and has provided recommendations and information regarding EUA requests for COVID-19 diagnostic tests in the EUA templates referenced in the Policy for Coronavirus Disease-2019 Tests. Examples of diagnostic testing include testing symptomatic individuals presenting to their healthcare provider, testing individuals who indicate that they were exposed to an individual with a confirmed or suspected case of COVID-19, and testing all individuals present at an event where an attendee was later confirmed to have COVID-19.
A: Yes. Laboratories performing molecular diagnostic COVID-19 tests for the qualitative detection of SARS-CoV-2 report test results as being positive or negative. Under the molecular diagnostic emergency use authorizations (EUAs), laboratories can also report cycle threshold (Ct) values for authorized molecular diagnostic COVID-19 tests they perform. Ct values indicate the number of amplification cycles needed to reach the threshold at which a molecular diagnostic test can detect a positive signal. Ct values are not comparable between tests and may not be comparable between different lots of the same test, as they are dependent on various factors such as the specimen collection, storage, transport, time from collection, nucleic acid target, primers and probes, extraction method, amplification method, instruments used, etc. Therefore, if the same sample from an individual is tested with two different tests, or even the same test from different lots, they are likely to return different Ct values, even if both tests return a "positive" test result.
While a low Ct value is generally considered to indicate a higher viral load in a patient specimen (i.e., less amplification is needed to detect a positive), and a high Ct value is generally considered to indicate a lower viral load in a patient specimen (i.e., more amplification is needed to detect a positive), currently there is no consensus as to whether or not particular Ct values correlate with a person being or not being infectious or risk level for disease severity. So, appropriate care should be taken with interpretation of Ct values.
A: Antibody testing is not currently recommended to assess immunity to COVID-19 after a COVID-19 vaccination. More research is needed in people who have received a COVID-19 vaccination. While a positive antibody test result can be used to identify antibodies that are part of the body’s immune response to SARS-CoV-2 infection, it should not be used to evaluate a person’s level of immunity or protection from COVID-19 at this time.
Since vaccines induce antibodies to specific viral protein targets, post-vaccination antibody test results will be negative in persons without history of previous natural infection if the test used does not detect the antibodies induced by the vaccine. Currently authorized SARS-CoV-2 antibody test results have not been evaluated to assess the level of protection provided by an immune response to COVID-19 vaccination. Health care providers considering antibody testing in vaccinated patients should follow the Centers for Disease Control and Prevention’s guidelines for antibody testing.