On September 19, 2025, FDA removed the language it had added to its diagnostic-test regulation the previous year. The agency restored the earlier text after a federal court vacated its laboratory-developed test rule.
The September rule implemented the court’s judgment. It did not establish a new exemption for every diagnostic test performed by a laboratory.
That distinction matters for organizations deciding what they can develop, offer, or distribute. Before 2024, FDA’s general enforcement-discretion policy did not cover every in vitro diagnostic product. After the court’s ruling, the separate question of FDA’s statutory authority also has to be answered.
Restoring the old wording did not make every test an LDT. It also did not simply restore FDA’s former claim that all LDT services were devices it could choose to regulate.
The Agency Removed the Rule After Losing the Authority Question
FDA’s May 2024 rule added language expressly including laboratory manufacturers in the regulatory definition of in vitro diagnostic products. Alongside that amendment, FDA announced a phased end to its broad LDT enforcement-discretion approach, subject to targeted policies.
On March 31, 2025, the Eastern District of Texas set aside the rule in American Clinical Laboratory Association v. FDA, remanding the matter to the Secretary. The court held that laboratory-developed testing services were professional medical services outside the FDCA’s device definition. It distinguished those services from commercially distributed diagnostic products, observing that neither side disputed that a laboratory making a test kit for commercial distribution is manufacturing a device. It also read CLIA as a separate framework under which Congress centralized laboratory oversight in HHS and CMS rather than FDA.
The ruling resolved a challenge to FDA’s statutory authority. It was not merely a decision to postpone compliance or strike a few burdensome requirements. FDA did not appeal, and the sixty-day window lapsed in early June 2025.
FDA’s September action then removed the added words from 21 CFR 809.3(a) and restored the section’s general citation to section 201(h) of the FDCA. The agency described the change as ministerial: the court had already vacated the rule. FDA’s current LDT page records the vacatur and restoration of the earlier text. The 2024 phaseout framework was set out in the preamble to the vacated rule and fell with it.
The Older Policy Had a Defined Subject
An in vitro diagnostic product is a broad category. It includes products used to examine specimens taken from the human body. An LDT was a narrower concept within FDA’s historical policy.
In its September 2023 description, FDA described LDTs as tests intended for clinical use and designed, manufactured, and used within a single clinical laboratory meeting applicable laboratory requirements. Its accompanying regulatory impact analysis identified CLIA certification and qualification for high-complexity testing.
The relationship among those activities mattered. A laboratory performing a test did not establish that it had also designed and manufactured that test. A company’s decision to call its offering an LDT did not establish that the offering matched FDA’s description.
Consider a laboratory that develops and performs its own testing method and reports results to an ordering clinician. Now consider a manufacturer that packages a diagnostic assay and ships it to other laboratories for them to perform. Both arrangements involve laboratory testing. They do not involve the same product or service.
The second arrangement falls outside the single-laboratory description. The purchaser’s CLIA certification does not transform the supplier’s distributed assay into an in-house test developed by that purchaser.
That is the essential limit in the earlier policy. Laboratory involvement was not enough to place every IVD within general LDT enforcement discretion.
LDT Status and Enforcement Discretion Were Different Questions
There is an important qualification. A test falling outside an enforcement-discretion policy did not necessarily cease to be an LDT. The description of the test and the agency’s decision whether to enforce particular requirements were separate questions.
FDA’s April 2019 warning letter to Inova Genomics Laboratory illustrates the difference. Inova invoked an LDT exemption for its MediMap pharmacogenetic tests. FDA responded that it had never established such an exemption and that its general practice of enforcement discretion did not prevent action to address significant public-health concerns.
The agency challenged claims about patients’ responses to named medications and asserted violations involving marketing authorization, stating that its concern was clinical validity rather than analytical validity. This was FDA’s enforcement position at the time, not a judicial finding establishing the accuracy or inaccuracy of every disputed claim.
The letter matters here because it predates the 2024 rule. FDA did not treat the phrase LDT as an unconditional promise that it would refrain from enforcement.
There were also limits associated with how tests were offered. FDA’s direct-to-consumer testing explanation describes its general nonreview policy for certain single-laboratory tests offered only on a healthcare provider’s prescription. That historical policy should not be converted into a categorical conclusion about FDA’s present authority over every consumer-facing testing service.
The Court Changed More Than the Wording
FDA’s earlier position treated LDTs as devices over which it exercised discretion. The judgment rejected that premise for laboratory-developed testing services. Statutory jurisdiction and enforcement policy must therefore be examined separately.
Enforcement discretion cannot supply authority the statute withholds. Conversely, the ruling does not remove FDA oversight of distributed diagnostic products merely because laboratories develop or use them.
The judgment also did not classify every possible arrangement involving multiple laboratories, outside developers, distributed components, or consumer-facing services. Those arrangements require analysis of their actual facts and the applicable law.
What Leaves the Laboratory Matters
Return to the two hypothetical businesses. One performs its own testing service. The other supplies an assay for other laboratories to run.
The regulatory review should identify what each business supplies. Is it reporting results from a service it performs, or distributing reagents, an instrument, or another diagnostic product? Who develops the method? Who manufactures the product? Where is it used? What claims accompany it?
A change in the business model can change those answers. A laboratory that begins supplying test kits to others has introduced a product-distribution activity that was absent from its in-house service. That activity needs its own analysis. The company’s existing LDT description cannot settle it.
This is a practical reason to revisit a regulatory assessment when a test is licensed, transferred, or commercialized differently. It is not a claim that every collaboration or transfer automatically creates an FDA-regulated device.
CLIA Obligations Continue
The vacatur did not remove the laboratory’s obligations under CLIA. For applicable tests developed in-house, modified from an FDA-cleared or approved system, or lacking manufacturer-provided performance specifications, 42 CFR 493.1253 requires the laboratory to establish specified performance characteristics before reporting patient results. Those characteristics include accuracy, precision, analytical sensitivity, and analytical specificity, as applicable.
Those requirements address laboratory performance. Compliance with them does not, by itself, establish FDA authorization for a separately regulated product or settle whether evidence supports every clinical claim made about a test.
