A federal court struck down the FDA’s final rule to regulate lab‑developed tests (LDTs), delivering a major legal setback to the agency’s 2025 regulatory agenda and punctuating a year dominated by contested attempts to expand diagnostics oversight. The decision halted a controversial rule that would have subjected many LDTs to the same premarket processes as commercial tests. Laboratory stakeholders celebrated the ruling as preserving flexibility for clinical labs, while proponents of stricter oversight warned about patient safety risks from less regulated tests. The court’s decision is likely to reshape agency strategies on diagnostics and may accelerate alternative policy routes, such as legislative efforts or targeted guidances.