The U.S. Food and Drug Administration proposed a rule to reclassify certain nucleic‑acid–based companion diagnostic assays from Class III to Class II, potentially allowing those tests to use the 510(k) pathway instead of premarket approval. The proposal targets in vitro diagnostics that detect genetic variants used with approved oncology therapeutics. Industry stakeholders noted the rule could lower development costs and shorten review timelines for companion diagnostics, opening competition to smaller diagnostic developers and clinical laboratories. The FDA emphasized continued postmarket surveillance, special controls and performance standards to ensure safety and effectiveness under reclassification. The proposal may change commercialization strategies for pharma‑diagnostic codevelopment, affect lab‑developed test dynamics and reshape how precision‑medicine diagnostics are validated and brought to market.