The Workbench · Craft
An LDT's compliance file still runs on CLIA, not FDA
This blog has already covered how FDA's own clearance decision and a separate CLIA categorization under 42 CFR 493 answer two different questions about the same commercial test. A laboratory-developed test never reaches the first of those two questions at all — it's never cleared, approved, or categorized by FDA, because it's never submitted. For most of the last decade FDA tried to close that gap by rule rather than by statute. The rule it finally finished didn't survive a year.
What an LDT is, and isn't
A laboratory-developed test is designed, validated, and performed entirely inside one CLIA-certified laboratory, on that laboratory's own patient specimens, without ever being manufactured for sale or distributed to another facility. That's the structural fact that kept LDTs outside FDA's device-clearance machinery for decades before this rule existed: the 510(k) and PMA pathways assume a device that leaves its maker's own four walls, and an LDT, by definition, doesn't. A test that does leave the lab — sold as a kit to other laboratories, or distributed as an instrument-reagent system — stops being an LDT at that point and becomes the kind of commercial IVD this blog has already covered, complete with its own clearance letter and its own CLIA categorization.
The rule that tried to close the gap
FDA's final rule, published in the Federal Register on May 6, 2024, took the position that an LDT had always met the FDCA's definition of a device, and that the agency's own decades-long general enforcement discretion toward the category was a policy choice it could simply stop making. The rule laid out a staged, four-year phase-out of that discretion — medical device reporting and complaint-file duties first, with compliance due within a year of the rule's effective date, then registration and listing, then quality system requirements including design controls, then premarket review itself for the highest-risk tests. None of it touched the statute. It rested entirely on FDA's own reading of what the statute already required.
The reading didn't hold
The American Clinical Laboratory Association sued, and in March 2025 the U.S. District Court for the Eastern District of Texas agreed with it: Judge Sean D. Jordan vacated the rule in its entirety, holding that the text, structure, and history of the FDCA and CLIA make clear that FDA lacks the authority to regulate laboratory-developed test services as devices. The clock on stage one's own duties never finished running. FDA didn't appeal, and by September 2025 the agency had moved to formally rescind the rule itself, reverting 21 CFR 809.3's definition of an in vitro diagnostic product to what it read before May 2024.
What never moved
CLIA's own validation duty was never part of what the court vacated, because it was never FDA's rule to begin with. 42 CFR 493.1253 has long required a laboratory performing nonwaived testing to establish, or verify, a test system's own performance specifications — accuracy, precision, reportable range, and whether the reference intervals in use actually fit its patient population — before a single patient result gets reported. That requirement runs through CMS and a lab's own high-complexity certificate, under a statute Congress passed for laboratory quality, not device marketing. It applied to an LDT before FDA's 2024 rule existed, kept applying while the rule's own phase-out clock was running, and applies today with the rule gone. The ground under it never actually moved.
What a compliance file should hold
A laboratory that spent 2024 and 2025 building a design history file, a device-style risk file, or a mock 510(k) submission against FDA's since-vacated timeline built real, often reusable work — validation data doesn't stop being validation data because the submission it was aimed at no longer exists. But the file an LDT actually has to defend today is the one 493.1253 asks for: the performance-specification study itself, the personnel qualification and proficiency-testing records a high-complexity certificate requires, and the quality-control record CLIA has asked for the entire time. A compliance program built around the submission that almost arrived, rather than the certificate requirement that never left, is tracking the wrong file.
Where this meets the file
A laboratory validation record built around 493.1253's own criteria — performance specifications established and verified, documented before reporting begins, and re-verified whenever the test or its intended population changes — is previewed in the launch catalog alongside this blog's other lab- and IVD-facing templates. If your lab has tracked this transition differently, the shelf takes that correction directly.
The Regulatory Toolkit launches soon — a free shelf of source-mapped templates, checklists and browser-only tools for regulatory teams. Get one email when it opens, or contribute a template.