Tempus AI agreed to acquire Personalis for about $1.5 billion, adding tumor-informed minimal residual disease (MRD) testing to its diagnostics platform. The deal values Personalis at $16.25 per share and is expected to close in late 2026 or early 2027, subject to shareholder and regulatory approvals. Personalis’ NeXT Personal assay uses whole-genome sequencing of the patient’s tumor to screen for residual disease, while Tempus brings tumor-naive MRD offerings and a multimodal data platform. Tempus said the combination is designed to support biomarker discovery and personalized oncology decisions, including recurrence monitoring. Personalis reported preliminary second-quarter revenue of $22.4 million and delivered 10,384 clinical tests, reflecting continued adoption. The acquisition follows a 2023 Tempus- Personalis commercial partnership to co-commercialize MRD testing. The purchase is the latest consolidation push in blood-based and MRD diagnostics as payers and oncology providers increasingly demand sensitive tools to detect residual disease after treatment.