Few regulatory questions have unsettled clinical laboratories over the past two years as much as the oversight of laboratory-developed tests. A final rule issued by the Food and Drug Administration (FDA) in 2024 sought to regulate such tests as medical devices and to phase out, over four years, the longstanding policy of enforcement discretion.¹ A federal court vacated that rule in March 2025, and in September 2025 the FDA formally rescinded the rule, restoring the regulatory definition of an in vitro diagnostic product to the language in effect before the rule took hold.^2-4 Oversight of laboratory-developed tests returned to the Centers for Medicare & Medicaid Services under the Clinical Laboratory Improvement Amendments, with enforcement discretion intact.

The relief, while real, has been widely misread. Vacatur of the rule did not erase the obligations that govern test validation, nor did vacatur alter the boundary that separates a research product from a clinical one. Reading the outcome as a green light invites exactly the kind of exposure the rule debate was meant to clarify. A legislative proposal introduced in 2026 by Rep. Neal Dunn, M.D. would, for the first time, place a statutory standard of analytical and clinical validity on laboratory-developed tests, a clear sign that the validation question is far from closed.⁵ With the threat of FDA oversight currently lifted, one practical question now carries more weight than before: does a given test represent a method that a laboratory developed and validated, or a kit assembled from components shipped in from elsewhere?

What the court decided, and what remained

The reasoning behind vacatur matters as much as the outcome. The court held that a laboratory testing service is a methodology or process rather than an article of commerce, and therefore not a device subject to regulation under the Federal Food, Drug, and Cosmetic Act.² The holding was specific and should not be overread. The same decision left undisturbed the agency’s authority over tangible products placed into commerce, a category that includes reagents, specimen collection kits, and the physical or software components distributed for use within a test. While the testing service itself moves outside device regulation, the components that a lab brings in from a supplier do not. The lab, however, still brings in components from a supplier that remain under FDA jurisdiction.

The boundary around research products was never part of the dispute. A product labeled for research use only must carry a statement restricting use to research, and such a product lacks assurance of the performance characterization, quality system conformity, and manufacturing controls expected of a clinical assay.⁶ Use of a research-use-only (RUO) product to make a clinical diagnosis falls outside permitted use regardless of how the broader landscape shifts. The jurisdictional line, in short, did not vanish with the rule. The line moved to a familiar place: the difference between a service that a laboratory performs and a product that a laboratory or a supplier ships.

A developed test versus a purchased one

The RUO framework does not assure that a component arrives with the clinical performance work and claims that accompany an FDA-cleared in vitro diagnostic (IVD) device. A given supplier may have characterized a great deal or very little; either way, establishing performance for the intended clinical use falls to the lab, and so does the full cost.

Three points sharpen the distinction. First, the obligation to validate does not transfer with a purchase. Under the Clinical Laboratory Improvement Amendments, a laboratory that introduces any method not cleared or approved by the agency must establish performance specifications for that method, including accuracy, precision, reportable range, and reference intervals appropriate to the population served.⁷ Establishing those specifications extends to qualifying any research-use-only components incorporated into the test. Purchasing components and following a supplied protocol does not satisfy that obligation, and a laboratory unable to produce a validation file in-house is not, in any meaningful sense, running a laboratory-developed test.

Second, the components remain within the agency’s reach. The research-use-only label is not a formality; it restricts the product to research and does not assure clinical validation.⁶ Marketing or deploying such a product for patient care has drawn enforcement attention, and warning letters addressing research-use-only reagents promoted for clinical purposes continue to be an issue.⁸ Regardless of the manufacturer’s claims, the burden of validation still falls on the laboratory.

Third, the direction of policy reinforces the same distinction. The 2026 legislative proposal would establish a statutory standard of analytical and clinical validity and would treat a commercially distributed protocol intended for use by unaffiliated laboratories as outside the definition of a laboratory-developed test, and potentially as a device subject to regulation.⁵ The developed-versus-purchased boundary, in other words, is being drawn the same way by the proposed statute as by sound laboratory practice.

Viewed through cost and risk together, the assembled-kit position carries the most exposure of available options. Such an approach carries the expense of purchased components alongside the full burden of in-house validation and clinical liability. It does so without the assurance of manufacturing controls maintained under FDA oversight that accompanies a cleared product, and in some circumstances may heighten regulatory exposure rather than reduce it.

Weighing the three pathways

No single pathway is superior in the abstract; the available pathways differ in the distribution of cost, control, and responsibility. A cleared in vitro diagnostic arrives with validation already reviewed, which lowers the validation burden on the laboratory but raises acquisition cost and limits flexibility to adapt the test to local needs.⁴ A genuine laboratory-developed test places the validation burden squarely on the laboratory, which raises both the workload and the accountability, yet preserves the flexibility to address unmet clinical needs and to adapt quickly, the very capacity the court sought to protect.² A research-use-only product is offered for research rather than diagnosis, so the entire diagnostic validation, and its cost, rests with the laboratory that puts it to clinical use.⁶ An IVD product, by contrast, has been through rigorous analytical and clinical validation before reaching the market, at the expense of the manufacturer.

Where a cleared IVD is available, it offers a validation already established and reviewed against the intended use. That validation also sits within a broader quality system: under FDA oversight, a cleared product is manufactured under controls for reproducibility, traceability, and lot-to-lot consistency, which is a genuine advantage.

What self-governance now requires

The most consequential control now available to a laboratory is the choice, when a cleared IVD exists for the intended use, to leverage the assurance the manufacturer has already built in. That assurance covers validation established and reviewed against the intended use, and a quality system maintaining reproducibility, traceability, and lot-to-lot consistency under FDA oversight. Choosing the cleared product secures that work at the outset, before the test reaches the bench.

One perspective in the continuing debate deserves mention, offered as a single view among several rather than as settled conclusion. A middle path, in which validations are independently reviewed without the full weight of premarket approval, would pair rigor with access, an arrangement glimpsed during the recent public health emergency. The emergency use pathways were imperfect, but they demonstrated that agency oversight need not come at the expense of innovation or speed. The 2026 legislative proposal contemplates a version of precisely that arrangement, through a voluntary affirmation of validity by a qualified, CMS-approved third party.⁵ A laboratory-developed test earns its place when no cleared product exists, preserving the flexibility to meet a clinical need that nothing else addresses. When a cleared IVD is available, the choice carries quiet weight: it brings validation already established and reviewed for the intended use, within a quality system that holds reproducibility, traceability, and lot-to-lot consistency under FDA oversight. None of this lifts the laboratory's responsibility for the result it reports, but it places much of the groundwork in proven hands before the first sample is run.

References

1. Food and Drug Administration. Medical devices; Laboratory developed tests. Federal Register. https://www.federalregister.gov/d/2024-08935. 
2. American Clinical Laboratory Association v United States Food and Drug Administration (consolidated with Association for Molecular Pathology v United States Food and Drug Administration). US District Court for the Eastern District of Texas; March 31, 2025.
3. Food and Drug Administration. Regulation identification number 0910-AJ05 medical devices; Laboratory developed tests; Implementation of vacatur. Federal Register. https://www.federalregister.gov/d/2025-18239. 
4. 21 CFR part 809 -- in vitro diagnostic products for human use. Ecfr.gov. Accessed July 8, 2026. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-H/part-809. 
5. Enhancing Clinical Laboratory Innovation and Access Act of 2026. HR 8890, 119th Cong (2026). Introduced May 19, 2026. Accessed July 8, 2026. https://www.congress.gov/bill/119th-congress/house-bill/8890/titles. 
6. Distribution of In Vitro Diagnostic Products Labeled for Research Use Only or Investigational Use Only: Guidance for Industry and Food and Drug Administration Staff. US Food and Drug Administration. November 2013. Accessed July 8, 2026. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/distribution-in-vitro-diagnostic-products-labeled-research-use-only-or-investigational-use-only. 
7. 42 CFR 493.1253 -- Standard: Establishment and verification of performance specifications. Ecfr.gov. 1253. Accessed July 8, 2026. https://www.ecfr.gov/current/title-42/chapter-IV/subchapter-G/part-493/subpart-K/subject-group-ECFRc96daead380f6ed/section-493.1253. 
8. Warning Letters. US Food and Drug Administration. Updated July 7, 2026. Accessed July 8, 2026. https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/compliance-actions-and-activities/warning-letters.