Castle Biosciences, Inc

Castle Biosciences is operationally centered in the United States, where it generates essentially all of its commercial testing revenue and maintains its sales and medical affairs organization. In 2025 it operated laboratory facilities in Phoenix, Arizona and Pittsburgh, Pennsylvania, both of which are CLIA-certified and CAP-accredited. The company’s laboratories are positioned to serve all 50 states, including jurisdictions with additional licensing requirements such as California, New York, Pennsylvania, Rhode Island, and Maryland. Geography matters mainly through reimbursement rules and state laboratory licensing, rather than through international manufacturing or export exposure.

Castle Biosciences is exposed to reimbursement risk because a large share of revenue depends on a relatively small number of third-party payors and Medicare coverage decisions. The company also faces clinical adoption risk: if clinicians do not view its tests as sufficiently useful or if competing staging criteria and alternative assays gain traction, test volumes can slow. Because the business relies on laboratory operations, it is exposed to regulatory and quality-control requirements tied to CLIA, CAP, and state licensing. More broadly, diagnostics companies face pricing pressure, evidence-generation costs, and the risk that new clinical guidelines or LCD changes can quickly alter demand and realized pricing.