FDA's Final Rule for Laboratory Developed Tests

At a Glance

• The FDA’s final rule — explicitly classifying in vitro diagnostic products including any laboratory developed tests (LDTs) as devices under the Federal Food, Drug, and Cosmetic Act — became effective on July 5, 2024.
• In addition to amending the FD&C Act, the final rule established a policy timeline for the FDA to phase out its longstanding history of general enforcement discretion of LDTs. The phase-out policy timeline is planned to be implemented in five separate stages taking place over a four-year period.

The FDA’s Webinar for Manufacturers and Other Interested Parties

The U.S. Food and Drug Administration (FDA) will host a webinar on February 25, 2025, from 2:00 p.m. EST to 3:00 p.m. EST, providing additional information about the investigational use requirements for in vitro diagnostic products (IVDs). These IVDs include any laboratory developed tests (LDTs).

The webinar is expected to describe or detail: the Investigational Device Exemptions (IDE) Regulation (21 CFR Part 812); the regulatory requirements it contains for the study of investigational devices; and the review process for the FDA’s IDE application. Additional details for the FDA webinar can be found here. There is no registration requirement. Please note that there is limited capacity for the FDA’s webinar, so the FDA recommends joining the webinar early.

The FDA Final Rule on LDTs

The FDA published its final rule on May 6, 2024, explicitly classifying IVDs as devices under the Federal Food, Drug, and Cosmetic Act (FD&C Act). The final rule became effective on July 5, 2024.

According to the final rule, the general enforcement discretion approach for LDTs led to an oversight scheme that did not “best serve the public health, and there is no longer a sound basis to have a bifurcated enforcement approach for LDTs and other IVDs.”¹ Additional justification from the FDA for the final rule was that LDTs evolved to the point that the FDA identified risks associated with their continued use, including: the high volume of LDT use for large and diverse populations; the increased complexity and instrumentation for generating LDT results; and the use of LDTs to direct critical treatment decisions, predict personal risk of certain diseases and diagnose serious medical conditions.

In addition to amending the FD&C Act, the final rule established a policy timeline for the FDA to phase out its longstanding history of general enforcement discretion of LDTs. The phase-out policy timeline is planned to be implemented in five separate stages taking place over a four-year period:

• On May 6, 2025, the FDA requires compliance with medical device reporting (MDR) requirements, correction and removal reporting requirements, and quality system (QS) requirements. At this stage, laboratories must track, investigate and report all adverse events, product recalls and customer complaints related to their LDT.²
• On May 6, 2026, the FDA requires compliance with medical device requirements in addition to MDR requirements. This means that the FDA will require compliance with registration, device listing, complaint files, correction and removal reporting, and investigational use requirements.³
• On May 6, 2027, all remaining QS laboratory processes not required during Stage 1, including auditing, controls, risk management and training, must comply with the Quality System regulations and requirements under 21 C.F.R. § 820, et seq.⁴
• On November 6, 2027, the FDA expects full compliance with premarket review requirements for high-risk IVDs.⁵ High-risk IVDs are classified into class III or are subject to licensure under Section 351 of the Public Health Services Act (biological products, including virus, serum, toxin, antitoxin, vaccine, blood, blood component or derivatives, allergenic products, proteins, or analogous products applicable to the prevention, treatment, or cure of a disease or condition for human beings.⁶
• On May 6, 2028, the FDA expects full compliance with premarket review requirements for both moderate- and low-risk IVDs, unless the FDA elects to exercise enforcement discretion for the applicable LDT.⁷

The final rule will have a significant impact on the future of LDTs and the laboratories that offer them. To date, there have been two legal challenges to the Final Rule, filed by the American Clinical Laboratory Association in May 2024 and the Association for Molecular Pathology in August 2024.