Laboratory-developed test
Laboratory-developed tests (LDTs) are tests created and used in a single laboratory to diagnose diseases or support research. They are valued for their flexibility and ability to spur innovation in diagnostics.
In the United States, LDTs have been regulated mainly under the Clinical Laboratory Improvement Amendments (CLIA) rather than through FDA premarket approval. The FDA classifies these tests as medical devices, but historically many LDTs entered the market without FDA clearance. The agency signaled in 2014 that it would start regulating some LDTs, but broad regulation had not been put in place as of 2019. Because LDTs do not require FDA 510(k) clearance, some see this as a regulatory loophole.
Direct-to-consumer tests (like some genetic tests) are treated as medical devices, but they are not always reviewed by the FDA. For example, 23andMe initially offered tests as LDTs, but the FDA required them to seek FDA approval as a Class II device.
Several companies develop LDTs, including Adaptive Biotechnologies, Quest Diagnostics, Roche, and Illumina.
The global market for LDTs is growing. It was about US$3.52 billion in 2023 and is projected to reach about US$4.58 billion by 2030, with a compound annual growth rate of around 3.8%. Growth is driven by advances in genetic testing, the move toward personalized medicine, and the expansion of healthcare and diagnostics.
This page was last edited on 3 February 2026, at 16:23 (CET).