One way FDA helps enable access to medical countermeasures (MCMs), such as in vitro diagnostic (IVD) tests, is through Emergency Use Authorizations (EUAs). An EUA allows FDA to authorize use of an unapproved MCM, in anticipation of a potential emergency or during an actual emergency involving a chemical, biological, radiological, or nuclear agent, or emerging infectious disease, if criteria in section 564 of the Federal Food, Drug, and Cosmetic Act are met.

On this page:

• Considerations When Choosing an IVD Test
• Search FDA Device Databases
• Implementing a Test: Getting Started
• Tri-Agency Task Force for Emergency Diagnostics (TTFED)
• EUA Termination or Revocation
• Using a Test: General Q&A
• Contact FDA

Considerations When Choosing an IVD Test

Patients, as well as their physicians, depend on FDA to ensure that the tests they use to make medical decisions are accurate, reliable, and clinically meaningful.
FDA requirements for many IVDs intended for clinical diagnostic use include premarket review through one of the following pathways:

• Premarket Approval (PMA)
• Premarket Notification (510(k)), or
• De Novo Classification 

Under certain emergency circumstances (as described in an HHS EUA declaration), FDA can enable access to an IVD based on less data (e.g., abbreviated analytical and clinical validation) than would be needed for a PMA, 510(k) or De novo, under an emergency access mechanism called an EUA, provided certain criteria are met: 

• the chemical, biological, radiological, or nuclear agent, including an emergent infectious disease, can cause a serious or life-threatening disease or condition;
• based on the totality of scientific evidence, it is reasonable to believe that the IVD may be effective in diagnosing the disease or condition;
• the known and potential benefits of the use of the IVD outweigh its known and potential risks; and
• there is no adequate, approved, and available alternative.  (Note:  FDA cannot issue an EUA for use of an IVD if there is available an adequate IVD legally marketed under a PMA, 510(k), or De novo).

Search FDA Device Databases

FDA offers a variety of Medical Device Databases to help you find an appropriate test:

• FDA’s searchable product databases for 510(k), PMA, and De Novo
• FDA’s list of EUAs
• Emergency Use Authorizations for Medical Devices

Hints for searching FDA databases

When searching the FDA databases for device products it can be helpful to know the product code of the device or group of devices. Alternatively, typing the pathogen name, e.g. Dengue or DENV, under the device/device name section can be helpful in identifying devices.

Additional information

To help laboratories decide which Zika IVD EUA test they may want to implement, FDA provides the following tables of key characteristics, performance characteristics, and instruments/methods:

• Table 1: Molecular ZIKV EUA Assays - Performance Characteristics (PDF, 200 KB)
• Table 2: Molecular ZIKV EUA Assays - Key Characteristics (PDF, 247 KB)

Implementing a Test:  Getting Started

Important information for laboratories with regard to a specific IVD authorized for use under an EUA can be found in the EUA Authorization Letters.  Since 2018, FDA has also been copying relevant information from the Authorization Letter in a section of the Instructions for Use entitled, “Conditions for Authorization for the Laboratory” that outline laboratory responsibilities when implementing an EUA IVD.

The Centers for Medicare and Medicaid Services published a memo to their surveyors explaining policy related to the Clinical Laboratory Improvement Amendments (CLIA) regulations as they apply to assays used under EUA. This memo discusses laboratory compliance with CLIA regulations and the verification of performance specifications for EUA IVD assays.

Tri-Agency Task Force for Emergency Diagnostics (TTFED)

The Tri-Agency Task Force for Emergency Diagnostics (TTFED) with members from Centers for Disease Control and Prevention (CDC), FDA, and Centers for Medicare and Medicaid Services (CMS) was established to develop a process to collaborate on future emergency diagnostic response needs. In advance of an emergency, the TTFED will work to define, refine, and streamline interagency approaches for the implementation of Emergency Use Authorization (EUA) in vitro diagnostic (IVD) assays. During an emergency, the TTFED will provide a forum for discussion of agent- or response-specific EUA IVD assays to help facilitate rapid implementation of the assays in the U.S. healthcare system. The TTFED Charter outlining the task force scope of activities was signed in 2019 and is publicly available. Agency-specific actions and matters will continue to fall under each member agency’s respective statutory authorities. The TTFED will in no way involve itself in decision-making that is under the jurisdiction of a member agency.

• Charter: Tri-Agency Task Force for Emergency Diagnostics (PDF, 196 KB)
• FDA news release: FDA, CDC, and CMS launch task force to help facilitate rapid availability of diagnostic tests during public health emergencies (February 26, 2019)

EUA Termination or Revocation

In general, an EUA will remain in effect for the duration of the HHS EUA declaration under which it was issued. There are two mechanisms, termination or revocation, that result in an EUA test no longer being authorized:

1. If a supporting HHS EUA declaration is terminated, then the termination of all EUAs issued pursuant to the declaration occurs on the effective date of the termination of HHS’s declaration. On that date, such EUAs will no longer be in effect.
2. Individual EUAs may be revoked by FDA if the circumstances justifying its issuance no longer exist, the criteria for its issuance are no longer met, or other circumstances make revocation appropriate to protect the public health or safety.

A number of circumstances are described in more detail in the FDA Guidance Document: Emergency Use Authorization of Medical Products and Related Authorities. Some circumstances that may result in the revocation of individual EUAs include: reports of adverse events (number or severity) linked to, or suspected of being caused by, the EUA product; product failure; change in approval status of the EUA product (e.g., the same product receives full marketing authorization such as with a Premarket Approval (PMA) or granting of a De Novo classification request); request from the EUA holder to revoke the EUA (e.g., the product is no longer manufactured).

Since a criterion for the issuance of an EUA is that there is no adequate, approved, and available alternative, when an EUA product subsequently receives full marketing authorization, such product may be an adequate, approved and available alternative to EUA products.  In such cases, FDA anticipates providing notice of intent to revoke to the remaining relevant EUA holders and an invitation to the holder of the full marketing authorization to comment on the extent to which their product is or is not an adequate, approved, and available alternative to existing EUA products. While FDA is undertaking this revocation process, the current active EUA products remain authorized.

When an EUA is revoked or terminated, there will be a date beyond which the test(s) can no longer be used. The EUA holder of the revoked or terminated EUA is advised to instruct laboratories to discontinue use of and discard any remaining EUA product inventory in accordance with the terms of the revocation or termination.

Laboratories are also encouraged to routinely check FDA’s list of active EUA products for the latest list of active EUAs and any updates to the EUA product granted through amendment. EUA products that have been terminated as a result of the termination of the supporting HHS EUA declaration or revoked by FDA even though the HHS EUA declaration is still in effect, are immediately removed from FDA’s active EUA products webpage. Information about EUAs that are no longer in effect is available on our EUA archive page. Notice of EUA revocations and terminations are also published in the Federal Register.

Using a Test:  General Q&A

1. How do I report performance concerns?

The letter of authorization will prescribe to whom and how to report performance concerns. Typically, laboratory personnel using diagnostic assays under EUA are encouraged to report performance concerns directly to FDA at [email protected], in addition to reporting concerns to the manufacturer.

2. Does an EUA test need to be used in a manner consistent with the authorized labeling?

Yes. Clinical diagnostic use of an IVD assay under EUA must follow the procedures outlined in the manufacturer’s Instructions for Use and the terms and conditions of authorization outlined in the authorization letter.  Deviations from the procedures outlined are not permitted under the EUA. For example, if a laboratory is requested to test specimens that are not authorized with the specific test, then testing the requested specimen would be an illegal use of the test. In this example, the laboratory is encouraged to contact FDA at [email protected].

3. Is it necessary to provide Fact Sheets with every test result?  Where can I find Fact Sheets?

When providing test results to healthcare providers and patients, laboratories must include a copy of the authorized fact sheets along with reports of the test results. Under exigent circumstances, other appropriate methods for disseminating fact sheets may generally be used, as described in the EUA Authorization Letter for a specific test, which may include mass media. Printable fact sheets specific for each EUA IVD are available on our EUA webpage.

4. Can I make changes to the test to improve it without contacting FDA?  Can laboratories develop the data necessary to add claims, instruments or specimen types, etc., to an existing EUA for an IVD?

An EUA IVD must be used as outlined in the Authorization Letter and Instructions for Use. If you have suggested improvements, then FDA recommends that you contact the EUA holder/ test manufacturer (contact information is provided in the authorized manufacturer’s Instructions for Use). The EUA holder can update their Instructions for Use in an amendment to the EUA, given FDA review of appropriate data.  Similarly, if a laboratory wishes to see a claim, instrument or specimen, etc., added to an existing EUA IVD then they should work with the EUA holder to amend the EUA.

5. What happens when an EUA is revoked or terminated?

If an EUA is revoked or terminated, then there will be a date beyond which the test can no longer be used for clinical diagnostic purposes. (See: Guidance: Emergency Use Authorization of Medical Products and Related Authorities section III.G.)

6. Where can I find information related to CLIA as applied to assays used under an EUA? 

The Centers for Medicare and Medicaid Services recently published a memo to their surveyors explaining policy related to the Clinical Laboratory Improvement Amendments (CLIA) regulations as they apply to assays used under an EUA. This memo discusses laboratory compliance with CLIA regulations and the verification of performance specifications for EUA IVD assays.

Contact FDA

If you have additional questions, contact [email protected].

Related links

• FAQs on EUAs for Medical Devices During the COVID-19 Pandemic
• FAQs on Testing for SARS-CoV-2
• COVID-19 EUAs for Medical Devices
• In Vitro Diagnostics EUAs (COVID-19)
• Virtual Town Hall Series - Coronavirus (COVID-19) Test Development and Validation 
• EUA Authorized Serology Test Performance
• Coronavirus (COVID-19) and Medical Devices