On October 3, 2023, the FDA published a proposed rule entitled “Medical Devices; Laboratory Developed Tests.” Following publication of the proposed rule, the FDA has received requests for an extension of the comment period. After considering the requests and other factors, including the extensive background of public comment on this topic and the public health benefits of proceeding expeditiously, the FDA has determined to proceed with the standard 60-day comment period. As stated in the notice of proposed rulemaking, comments on the proposed rule must be submitted to the docket by December 4, 2023, in accordance with the procedures described in the notice.
On This Page:
- Increased FDA Oversight to Help Ensure Safety and Effectiveness of LDTs
- Historical LDT Related Links
Laboratory developed tests, or LDTs, 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 clinical laboratory which meets certain laboratory requirements. Specifically, such laboratory must be certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) and meet 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, analytes, or markers 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 tests have been raised for many years.
Although historically the FDA has generally exercised enforcement discretion over most LDTs, meaning that the agency generally has not enforced applicable requirements with respect to most LDTs, the risks associated with most modern LDTs are much greater than the risks that were associated with LDTs used decades ago. In the 1970s and 1980s, many LDTs were lower risk, small volume, 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 are also increasingly relying on high-tech instrumentation and software, being performed in large volumes, and being used more frequently to help guide critical health care decisions.
Due to evolution and proliferation of LDTs, as well as the 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 safe and effective to make good health care decisions. These assurances are lacking for IVDs offered as LDTs without active FDA oversight. False test results or false claims regarding the meaning of test results can lead to significant patient harm.
On September 29, 2023, the FDA announced a proposed rule aimed at helping to ensure the safety and effectiveness of these tests. The proposed rule seeks to amend 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 is proposing a policy under which the FDA intends to provide greater oversight of LDTs through a phaseout of its general enforcement discretion approach for most LDTs.
- Proposed Rule: Medical Devices; Laboratory Tests
- FDA Proposes Rule Aimed at Helping to Ensure Safety and Effectiveness of Laboratory Developed Tests
- Genetic Non-Invasive Prenatal Screening Tests May Have False Results: FDA Safety Communication
- Public Health Evidence for FDA Oversight of Laboratory Developed Tests: 20 Case Studies – The real and potential harms to patients and to public health from certain laboratory developed tests (LDTs) – November 16, 2015
- Public Workshop – Oversight of Laboratory Developed Tests, July 19-20, 2010
- Notification to Congress: FDA’s Laboratory Developed Tests Framework – July 31, 2014 (PDF - 991KB)
- Blueprint for Breakthroughs - Charting the Course for Precision Medicine
- FDA Discussion Paper on Laboratory Developed Tests (LDTs) (PDF - 180KB)