FDA’s LDT Rule Vacated: What This Means for Laboratory Diagnostics

April 2, 2025

The FDA LDT rule vacated by Judge Sean D. Jordan on March 31, 2025, marks a landmark decision for clinical laboratories across the United States. This ruling fundamentally reshapes the regulatory landscape for diagnostic testing by determining that the Food and Drug Administration lacks statutory authority to regulate Laboratory Developed Tests (LDTs) as medical devices under the Federal Food, Drug, and Cosmetic Act.

Key Takeaways:

• • The FDA’s rule to regulate LDTs as medical devices has been vacated by federal court
  • Judge ruled the FDA lacks statutory authority to regulate laboratory services
  • Laboratories will not need to comply with the FDA’s phased implementation plan
  • LDTs will continue to be regulated under existing CLIA framework

Understanding LDTs and Their Regulatory History

Laboratory Developed Tests are designed, manufactured, and used within a single laboratory certified under the Clinical Laboratory Improvement Amendments (CLIA) to perform high-complexity testing. For decades, the FDA exercised “enforcement discretion” over LDTs, meaning that while the agency claimed authority to regulate these tests as medical devices, it generally chose not to enforce regulatory requirements.

As technology advanced, LDTs evolved to become increasingly complex and widely used, prompting the FDA to reconsider its approach. Over the past decade, the FDA made several attempts to increase oversight:

• • 2014: Draft guidance documents proposing a framework for LDT regulation
  • 2017: FDA discussion paper on possible approaches to oversight
  • 2023-2024: Congress explored legislative solutions through the VALID Act, which never passed

After these unsuccessful efforts, the FDA took direct regulatory action in May 2024.

What the FDA Rule Would Have Required

The FDA’s final rule explicitly classified LDTs as medical devices under the Federal Food, Drug, and Cosmetic Act. This would have subjected laboratories to a phased implementation of requirements over four years:

1. 1. Stage 1 (May 2025): Medical device reporting and complaint files requirements
   2. Stage 2 (May 2026): Registration, listing, and labeling requirements
   3. Stage 3 (May 2027): Quality System requirements
   4. Stage 4 & 5 (Nov 2027-May 2028): Premarket review requirements for high, moderate, and low-risk LDTs

The laboratory community largely opposed these requirements, arguing they would create redundant regulations, increase costs, and potentially limit patient access to essential diagnostic tests.

The Court’s Decision and Reasoning

Judge Jordan’s ruling was definitive. The court found that the FDA lacks statutory authority to regulate LDTs, determining that a “device” under federal law is “a tangible, manufactured product, not a professional service.”

The decision emphasized that Congress had already established a regulatory framework for laboratory services through CLIA, vesting authority in CMS, not the FDA. The court vacated the FDA’s rule in its entirety and remanded the case for further consideration.

Immediate Impact for Laboratories

For clinical laboratories, this ruling means:

• • No need to comply with the FDA’s May 2025 deadline for medical device reporting
  • Continued operation under existing CLIA regulations
  • Avoidance of potentially billions in additional healthcare costs
  • Preservation of the ability to develop and implement new tests without FDA oversight

As Jane S. Gibson, President of the Association of Molecular Pathology (AMP), stated, this ruling “will avoid adding billions of dollars to healthcare costs and protect access to high-quality care for hundreds of millions of Americans.“

What’s Next for LDT Regulation?

While the court’s decision represents a victory for laboratory advocates, the future regulatory landscape remains uncertain. Several possibilities exist:

1. 1. Potential Appeal: The FDA could appeal the ruling, though the current administration’s approach is unclear
   2. Legislative Action: Congress might revisit creating a clearer statutory framework
   3. Modified FDA Approach: The agency might craft a more limited regulatory framework
   4. Enhanced CLIA Oversight: CMS could strengthen CLIA requirements for LDTs

Organizations like the American Clinical Laboratory Association (ACLA) and the Association of Molecular Pathology (AMP) have been at the forefront of opposing FDA regulation of LDTs and will likely continue to engage with lawmakers on future regulatory approaches. These groups maintain that laboratory services are already appropriately regulated under CLIA while acknowledging the importance of test quality and patient safety.

The Trump administration will also play a significant role in determining next steps, as any appeal decision would come from the Department of Justice in consultation with FDA leadership. Industry observers will be watching closely for signals about the administration’s regulatory priorities in this space.

Balancing Innovation and Safety

This ruling preserves the autonomy of clinical laboratories to develop and implement tests that meet critical healthcare needs without additional regulatory burden. For patients, it helps ensure continued access to specialized diagnostic tests that might otherwise have been discontinued due to regulatory costs.

However, the question of how to best ensure test quality remains. The laboratory community now has an opportunity to engage with regulators and lawmakers to develop approaches that both protect patients and foster innovation in diagnostic medicine.

This article is for informational purposes only and does not constitute legal advice. Laboratories should consult with their legal counsel regarding regulatory compliance matters.