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Laboratory Developed Tests

April 29, 2024: The FDA announced a final rule aimed at helping to ensure the safety and effectiveness of laboratory developed tests (LDTs). The rule amends the FDA's regulations to make explicit that in vitro diagnostic products (IVDs) are devices under the Federal Food, Drug, and Cosmetic Act (FD&C Act) including when the manufacturer of the IVD is a laboratory. Along with this amendment, the FDA is finalizing a policy under which the FDA will provide greater oversight of IVDs offered as LDTs through a phaseout of its general enforcement discretion approach for LDTs over the course of four years, as well as targeted enforcement discretion policies for certain categories of IVDs manufactured by laboratories.

On May 14, 2024, the FDA will host a webinar to provide an overview of the final rule, including the phaseout policy. If you have questions that you wish to submit for possible discussion during the webinar, please email CDRHWebinars@fda.hhs.gov. All questions must be received by May 7, 2024, to be considered for the discussion. Questions will be not be taken during the live webinar. Following this, the FDA intends to host additional webinars focusing on specific topics related to the phaseout policy. These will be announced as they are scheduled.

A list of existing resources on device regulation is provided below. Additional resources related to the implementation of the phaseout policy will be added to this page as they become available. Additional information can also be found on Laboratory Developed Tests: Frequently Asked Questions.

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Background

Laboratory developed tests, or LDTs, can play an important role in healthcare. LDTs are in vitro diagnostic products (IVDs) that are intended for clinical use and are designed, manufactured, and used within a single laboratory that is certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) and meets the regulatory requirements under CLIA to perform high complexity testing.

IVDs are intended for use in the collection, preparation, and examination of specimens taken from the human body, such as blood, saliva, or tissue. LDTs, like other IVDs, can be used to measure or detect a wide variety of substances or analytes in the human body, such as proteins, glucose, cholesterol, or DNA, to provide information about a patient's health, including to diagnose, monitor, or determine treatment for diseases and conditions.

IVDs offered as LDTs are used in a growing number of health care decisions, and concerns about the safety and effectiveness of these IVDs have been raised for many years.

In implementing the Medical Device Amendments of 1976, the FDA generally exercised enforcement discretion for most LDTs, meaning that the agency generally has not enforced applicable requirements with respect to most LDTs. However, the risks associated with most modern LDTs are much greater than the risks associated with LDTs used decades ago. At that time, many LDTs were lower risk, performed in small volumes, and used for specialized needs of a local patient population. Since then, due to changes in business practices and increasing ability to ship patient specimens across the country quickly, many LDTs are now used more widely, for a larger and more diverse population, with large laboratories accepting specimens from across the country. LDTs also increasingly rely on high-tech instrumentation and software, are performed in large volumes, and are used more frequently to help guide critical health care decisions. The FDA is now phasing out the general enforcement discretion approach for LDTs, as discussed below. The phaseout policy is intended to better protect the public health by helping to assure the safety and effectiveness of IVDs offered as LDTs, while also accounting for other important public health considerations such as patient access and reliance.

Increased FDA Oversight to Help Ensure Safety and Effectiveness of LDTs

Due to the evolution and proliferation of LDTs, as well as increasing concerns regarding their safety and effectiveness, the FDA has engaged in discussions regarding increased oversight of LDTs for many years, including holding a workshop in 2010, proposing draft guidance documents in 2014, issuing a discussion paper in 2017, and engaging with congressional and industry stakeholders. Throughout this time, the FDA has maintained that patients and healthcare providers need assurances that the tests they are using are appropriately safe and effective to make good health care decisions. These assurances are lacking for IVDs offered as LDTs without more active FDA oversight. False test results or false claims regarding the meaning of test results can lead to significant patient harm.

On October 3, 2023, the FDA issued a proposed rule aimed at helping to ensure the safety and effectiveness of these IVDs. On April 29, 2024, the FDA announced it had finalized this rulemaking. The final rule amends the FDA's regulations to make explicit that IVDs are devices under the Federal Food, Drug, and Cosmetic Act including when the manufacturer of the IVD is a laboratory. Along with this amendment, the FDA finalized a policy under which the FDA will provide greater oversight of IVDs offered as LDTs through a phaseout of its general enforcement discretion approach for LDTs over the course of four years. The phaseout includes targeted enforcement discretion policies for certain categories of IVDs manufactured by laboratories.

Phaseout Policy

As discussed in the phaseout policy, following a four-year period, IVDs offered as LDTs generally will be expected to meet applicable requirements, though certain IVDs may fall within targeted enforcement discretion policies, as discussed below.

The phaseout policy contains the following five stages:

  • Stage 1: beginning on May 6, 2025, which is 1 year after the publication date of the final LDT rule, FDA will expect compliance with medical device reporting (MDR) requirements, correction and removal reporting requirements, and quality system (QS) requirements regarding complaint files.
  • Stage 2: beginning on May 6, 2026, which is 2 years after the publication date of the final LDT rule, FDA will expect compliance with requirements not covered during other stages of the phaseout policy, including registration and listing requirements, labeling requirements, and investigational use requirements.
  • Stage 3: beginning on May 6, 2027, which is 3 years after the publication date of the final LDT rule, FDA will expect compliance with QS requirements (other than requirements regarding complaint files which are already addressed in stage 1).
  • Stage 4: beginning on November 6, 2027, which is 3½ years after the publication date of the final LDT rule, FDA will expect compliance with premarket review requirements for high-risk IVDs offered as LDTs (IVDs that may be classified into class III or that are subject to licensure under section 351 of the Public Health Service Act), unless a premarket submission has been received by the beginning of this stage in which case FDA intends to continue to exercise enforcement discretion for the pendency of its review.
  • Stage 5: beginning on May 6, 2028, which is 4 years after the publication date of the final LDT rule, FDA will expect compliance with premarket review requirements for moderate-risk and low-risk IVDs offered as LDTs (that require premarket submissions), unless a premarket submission has been received by the beginning of this stage in which case FDA intends to continue to exercise enforcement discretion for the pendency of its review.

The FDA also intends to exercise enforcement discretion and generally not enforce some or all applicable requirements for certain categories of IVDs manufactured by a laboratory. Please refer to the preamble to the rule for the details and policies.  

Webinars

The FDA intends to hold a webinar on May 14, 2024, to provide an overview of the final rule and phaseout policy.

The FDA intends to hold additional webinars focusing on specific topics related to the phaseout policy.

  • June 2024: Tentative topic: Draft Guidances on Enforcement Policy for Certain In Vitro Diagnostic Devices for Immediate Public Health Response in the Absence of a Declaration Under Section 564 (applicable to LDTs) and Consideration of Enforcement Policies for Tests During a Section 564 Declared Emergency (applicable to IVDs)
  • July 2024: Tentative topic: IVD Classification
  • August 2024: Tentative topic: MDRs, Quality System Complaint Requirements, and Recalls

To submit questions to be answered during the webinars, email CDRHWebinars@fda.hhs.gov at least one week prior to the webinar.

Medical Device Regulatory Resources

Related Links

Historical LDT Related Links



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