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# Laboratory-Developed Test Decision Reviewed
- URL: https://www.fdaweb.com/laboratory-developed-test-decision-reviewed/
- Published: 2025-04-08T12:00:00.000Z
- Updated: 2026-09-14T14:57:13.000Z
- Author: David McFarland
- Tags: Devices, #legacy-id-D5158972

Six Sidley attorneys say that a Texas federal court’s 3/31 [decision](https://www.fdaweb.com/fda-loses-on-regulating-lab-developed-tests/) throwing out FDA’s final rule on oversight of laboratory-developed tests (LDTs) relied heavily on the Supreme Court’s 2024 *Loper Bright* decision that eliminated the precedent of courts deferring to agency interpretations of unclear laws. The Sidley [analysis](https://www.sidley.com/en/insights/newsupdates/2025/04/fdas-laboratory-developed-tests-ldt-rule-struck-down-in-major-test-of-loper-bright?ref=fdaweb.com) says the ruling “raises many questions about how LDTs will be regulated, including whether the new administration will seek to stay or appeal the ruling and whether Congress will extend explicit statutory authority to FDA to regulate LDTs.”

The attorneys write that the court leaned heavily on *Loper Bright* despite its conclusion that the pertinent statutory language is unambiguous. They say the decision emphasized *Loper*’s caution that courts “must exercise their independent judgment in deciding whether an agency has acted within its statutory authority” and “independently identify and respect \[constitutional\] delegation of authority, police the outer statutory boundaries of those delegations, and ensure that agencies exercise their discretion consistent with the Administrative Procedures Act.”

The post outlines several practical questions the authors say face FDA and clinical laboratories:

- how the decision will affect the 5/2025 implementation date for the final rule that would have affected nearly 80,000 existing tests offered by about 1,200 laboratories;
- whether the government will appeal and/or seek a stay of the decision;
- even if there is no appeal, whether FDA might continue to take the position that some tests offered by laboratories do not fall within the scope of the decision and thus are still subject to medical device regulation;
- the status of tests offered by companies that have already taken actions in recognition of FDA’s claimed authority over their tests;
- whether HHS or FDA will issue a public statement on the decision’s implications; and
- whether Congress will take any action on legislation to create a new regulatory scheme for LDTs that might give some authority to FDA.