Public Health Implications of Legal Challenges to the FDA's Regulation of Laboratory-Developed Tests.

Abstract

Laboratory-developed tests (LDTs) refer to in vitro diagnostics developed and used by individual laboratories. LDTs are widely used in modern medicine, with their results informing over 70% of clinical decisions. The US Food and Drug Administration (FDA) has historically claimed regulatory authority over LDTs and, in 2024, finalized new regulations to strengthen oversight of these products. However, the FDA's rulemaking was vacated in the 2025 court case American Clinical Laboratory Association