Overview
On March 31, 2025, a federal court vacated the FDA's final rule attempting to regulate laboratory-developed tests (LDTs) as medical devices under the Federal Food, Drug, and Cosmetic Act (FDCA). The ruling is a significant victory for clinical laboratories across the country.
FDA regulates test kits (like home Covid test kits) as "medical devices" and has developed stringent requirements for their manufacture and sale. An LDT is a service, agreed between the patient's medical doctor and the medical doctor in the laboratory, to test the patient's specimen for various "analytes" (antibodies to viruses, hormones, viral particles, etc.). These tests are developed by the laboratory because manufactured kits are not available for the exact test the patient needs. The FDA had asserted a right to regulate LDTs as medical devices.
The advantage of LDTs is that they can be tailored to fit these needs quickly and for far less cost than asking a kit manufacturer to create a specialized test and obtain FDA approval. LDTs are regulated by the Center For Medicare and Medicaid Services (CMS) and the Clinical Laboratory Improvements Amendments (CLIA) which require the lab to "establish performance characteristics" --prove that the test works as claimed-- and retain the proof for inspection by CMS.
FDA's decision to regulate LDTs would have resulted in double regulation (CMS and FDA), slowed innovation and cost billions of dollars, which would ultimately be passed on the patient.
The rule would subject about 79,114 existing LDTs and 1,181 labs to FDA premarket reviews, post-market surveillance, and quality system requirements. "FDA acknowledged that the costs of the proposed rule would be significant. Specifically, it estimated that the cost of preparing and submitting [applications] for existing laboratory-developed tests would exceed $35 billion and could reach $113 billion. It also projected that, going forward, annual compliance costs for affected laboratories would range from $4 billion to $14 billion." (From the judgment linked below.)
On March 31, 2025, a federal court vacated the FDA's rule to regulate LDTs as medical devices, marking a significant legal setback for the agency. Judge Sean D. Jordan of the U.S. District Court for the Eastern District of Texas ruled that the FDA lacks statutory authority under the Federal Food, Drug, and Cosmetic Act (FDCA) and CLIA to oversee LDTs, which he characterized as diagnostic services rather than physical medical devices.
The court emphasized that Congress designed CLIA as the primary regulatory framework for clinical laboratories, delegating oversight to CMS rather than the FDA. LDTs were deemed "proprietary methodologies" rather than physical devices, placing them outside the FDA’s jurisdiction.
Of course, FDA may appeal the decision, or Congress may act and change the requirements by law.
I know laboratories have already spent large amounts attempting to get ready for the May 2025 deadline. (I should have taken up the offer to act as a consultant...too late now.) My advice is to keep doing all the things the FDA has so far required. No harm, and possibly great good, will come from having properly documented complaints procedures and test development and change files beyond the original CLIA requirements.
