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last updated: 2026-02-28 AI
file_name: _AI_FDA 2024 LDT Rule - Status and Legal History.md
file_date: 2026-02-28
title: FloodLAMP FDA 2024 LDT Rule - Status and Legal History
category: regulatory
subcategory: ldts
tags: ldt, fda, regulation, enforcement-discretion, vacatur
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gfile_url: https://docs.google.com/document/d/14vtSNC5z-q58VK2eLzQdMLqvG8DG1jgZP0kG2IPFBeI
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license: CC BY 4.0 - https://creativecommons.org/licenses/by/4.0/
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words: 504
notes: Created by ChatGPT 5.2 thinking during archive preparation. **NOT HUMAN VERIFIED - MAY CONTAIN ERRORS** Overview of the FDA's 2024 final rule on laboratory-developed tests, the phaseout timeline, legal challenges, court vacatur, and current regulatory status as of February 2026.
summary_short: FDA 2024 LDT final rule overview and legal history, covering the phased enforcement-discretion rollback (2025--2028 milestones), the March 2025 Eastern District of Texas vacatur, FDA's decision not to appeal, and the September 2025 regulatory text reversion--returning LDT oversight to the pre-2024 status quo.


CONTENT

## What the FDA's 2024 LDT Rule Was

Laboratory-developed tests (LDTs) are in vitro diagnostic (IVD) tests that are designed, manufactured, and used within a single laboratory (as opposed to test kits sold broadly to many labs).

For decades, FDA generally took the position that many LDTs could fall within medical device/IVD authorities, but mostly exercised "enforcement discretion" (i.e., did not generally enforce device requirements like premarket review) for most LDTs.

In May 2024, FDA issued a final rule ("Medical Devices; Laboratory Developed Tests," 89 Fed. Reg. 37286) that aimed to end that broad enforcement discretion over time by:

- Amending the definition of "in vitro diagnostic products" in 21 C.F.R. Section 809.3(a) to explicitly include IVDs "including when the manufacturer ... is a laboratory."
- Creating a ~4-year, staged phaseout of enforcement discretion, gradually expecting labs offering LDTs to comply with device requirements. FDA's FAQ described the milestones like this:
  - May 6, 2025: adverse event reporting (MDR), corrections/removals reporting, and complaint files
  - May 6, 2026: registration/listing, labeling, and investigational use requirements
  - May 6, 2027: additional quality system requirements (with specific QS elements emphasized for LDTs)
  - Nov 6, 2027: premarket review for high-risk LDTs
  - May 6, 2028: premarket review for moderate-risk (and the subset of low-risk) LDTs that require it


## What Happened Legally (and the Current Status)

### 1) The Rule Was Struck Down (Vacated) in Federal Court
On March 31, 2025, the U.S. District Court for the Eastern District of Texas vacated the 2024 final rule in consolidated cases brought by laboratory groups (including ACLA and AMP), holding FDA lacked statutory authority under the FD&C Act to regulate LDTs as "devices" in the way the rule attempted--characterizing LDTs as medical test services rather than devices.

### 2) FDA Did Not Appeal
Multiple sources report the government declined to appeal within the deadline, leaving the district court decision in place.

### 3) FDA Formally Reverted the Regulation Text (Rescinded the 2024 Change)
After the vacatur, FDA issued a final rule on September 19, 2025 reverting 21 C.F.R. Section 809.3(a) back to its pre-2024 wording (i.e., removing the "including when the manufacturer...is a laboratory" language). FDA's own LDT page summarizes this sequence (final rule -> vacated -> reverted).

Reporting on the rollback likewise describes FDA rescinding the rule following the court decision.


## Where Things Stand Now (as of Feb 9, 2026)

- The FDA's 2024 LDT final rule is not in effect: it was vacated by the court and FDA did not appeal, and FDA then reverted the regulatory text to the pre-2024 version.
- Practically, that means the phaseout schedule (2025--2028 milestones) is no longer operative, and the regulatory landscape largely returns to the pre-2024 status quo (LDTs primarily overseen via CLIA laboratory regulation, with FDA continuing its traditional device oversight of commercial test kits/IVDs and certain other categories).
- The larger policy question (whether Congress gives FDA explicit LDT authority via new legislation) remains a live debate, but that is separate from the now-vacated 2024 rule.