UnitedHealthcare has agreed to cover Guardant Health’s Shield colorectal cancer screening test as a first-line assay, driving a sharp market reaction for Guardant stock. The insurer’s decision covers average-risk patients within specified age bands and includes a requirement for follow-up colonoscopy when results are abnormal. The coverage decision includes adults aged 45 to 75 who have not had Shield previously and meet average-risk criteria, as well as patients aged 76 to 85 who have never been screened by any method. Analyst commentary characterized the ruling as precedent-setting and expected to support average selling price and volume momentum beginning in August. Guardant also noted earlier coverage uptake from Tricare for Shield earlier in the year. The new UHC policy covers 30 million commercial lives, though Guardant’s benefit is limited by under-45 eligibility details and patient distribution. For biotech diagnostics, the decision is another high-impact reimbursement milestone for liquid biopsy colorectal screening and may influence payer contracting decisions beyond the initial coverage group.