FDA Takes Action to Ensure the Safety and Effectiveness of Laboratory Developed Tests

"The final rule announced today ensures that health care decisions are based on reliable test results." - Robert M. Califf, M.D.

by | May 30, 2024

Today, the U.S. Food and Drug Administration (FDA) took significant steps to enhance the safety and effectiveness of laboratory-developed tests (LDTs), which are increasingly pivotal in healthcare decisions. Concerns about these tests have been raised for many years.

Understanding Laboratory-Developed Tests (LDTs)

LDTs are in vitro diagnostic products (IVDs) designed, manufactured, and used within a single clinical laboratory meeting specific regulatory requirements. These tests are crucial for diagnosing and monitoring various health conditions by examining specimens, such as blood, saliva, or tissue. They measure substances like proteins, glucose, cholesterol, or DNA to provide essential health information.

FDA’s New Regulations for IVDs and LDTs

The FDA has issued a final rule clarifying that IVDs, including those manufactured by laboratories, are considered devices under the Federal Food, Drug, and Cosmetic Act (FD&C Act). This amendment marks the beginning of a four-year phase-out of the FDA’s general enforcement discretion for LDTs. Additionally, the FDA has implemented targeted enforcement policies for specific IVD categories produced by laboratories.

Ensuring Reliable Healthcare Decisions

FDA Commissioner Robert M. Califf, M.D., emphasized the necessity of these changes, stating, “LDTs are now used widely for critical purposes, including newborn screening and cancer risk prediction. The final rule announced today ensures that health care decisions are based on reliable test results.”

Addressing Modern Lab Developed Tests LDT Risks

Historically, the FDA exercised enforcement discretion for most LDTs, focusing on lower-risk, small-volume tests. However, the modern use of LDTs involves higher risks, advanced technology, and larger patient populations. The FDA has identified numerous instances where inaccurate or ineffective LDTs have caused patient harm, including tests for cancer treatment and COVID-19 diagnosis.

Protecting Patients and Reducing Health Care Costs

Increased oversight will mitigate the risks of inaccurate LDT results, preventing unnecessary treatments and ensuring proper care. This change aims to reduce healthcare costs by avoiding ineffective or misleading tests.

Promoting Innovation and Health Equity

Enhanced compliance with the FD&C Act will foster confidence in IVDs regardless of their manufacturing location. The FDA’s oversight will also support better representation in validation studies and transparency about test performance across diverse patient populations, advancing health equity.

Future of Lab Develop Lab Developed Tests LDT Regulation

Jeff Shuren, M.D., J.D., director of the FDA’s Center for Devices and Radiological Health, highlighted the importance of today’s action. “This step ensures the safety and effectiveness of LDTs while maintaining access to critical tests. The targeted enforcement policies will help patients and healthcare professionals trust the tests they rely on.”

Phaseout Policy and Enforcement Discretion

The FDA will phase out its general enforcement discretion for LDTs over four years, ensuring a smooth transition for laboratories and continued patient care. The FDA will exercise enforcement discretion for certain IVD categories, including:

  • IVDs offered as lab-developed tests LDTs marketed before the final rule’s issuance.
  • LDTs manufactured within healthcare systems to meet unmet patient needs where no FDA-authorized test is available.
  • Lab Developed Tests LDTs approved by New York State’s Clinical Laboratory Evaluation Program (CLEP).

These policies are designed to balance patient access to essential tests while ensuring their safety and effectiveness.


The FDA’s new regulations for LDTs and IVDs aim to protect public health by ensuring the accuracy and reliability of these tests. This move will enhance patient care, reduce healthcare costs, and promote innovation in diagnostic testing.

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  • Pam Wertalik

    Passionate science/technology entrepreneur and founder of, the first web-based platform for laboratory outsourcing and scientific sourcing. . Proud, award-winning former FDA, US Food and Drug Administration Consumer Safety Officer, Medical Device Specialist, International Cadre.

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