LDTs in Flux: Will Evolving Regulations Enhance or Complicate Laboratory Practices?

Clinical labs help diagnose and manage disease by testing blood and other specimens. They operate under federal rules known as Clinical Laboratory Improvement Amendments (CLIA). Most tests are FDA cleared/approved, but some are laboratory-developed tests (LDTs) created in individual labs, typically to meet unmet needs. LDTs have long existed in a complicated regulatory space. In 2024, the FDA issued a rule to regulate LDTs like devices, prompting concerns about cost, innovation, and access. A federal court struck the rule down in 2025, finding LDTs are services, not devices. The FDA subsequently rescinded its rule. In this article, experts argue that LDTs are essential and already held to strong standards and that future reforms should strengthen CLIA while protecting access and innovation.