CareDx provides blood-based molecular diagnostic tests for organ transplant patients. The core product suite — AlloSure Kidney, AlloSure Lung, AlloMap Heart, and HeartCare (a combined heart surveillance product) — detects signs of organ rejection using donor-derived cell-free DNA and gene expression profiling. These tests are designed to replace or reduce reliance on invasive biopsies, allowing transplant clinicians to monitor patients through routine blood draws. CareDx serves roughly 250 U.S. transplant centers through a direct sales force, with international distribution through country managers and distributors. The business model is built on recurring per-test billing: each time a clinician orders a test, CareDx performs it at its CLIA-certified lab in Brisbane, California, and bills the patient's insurer. Because transplant patients require lifelong monitoring, a single patient on a surveillance protocol generates recurring test orders for years. Testing Services represents roughly 72% of revenue, with the remainder split between Patient and Digital Solutions — transplant center software, a specialty pharmacy, and remote monitoring tools — and Lab Products, which are HLA typing kits sold globally to transplant labs for donor-recipient matching. CareDx argues that bundling these three offerings into a single transplant center engagement drives higher testing adoption and patient adherence. Medicare reimbursement at CMS-set rates accounts for roughly half of testing services revenue, making reimbursement policy a key risk. CareDx is also expanding into hematologic malignancies with AlloHeme, a blood-based test targeting relapse detection in stem cell transplant patients.