Oak Street Health
2023
$10.6B
Why
CVS acquired Oak Street Health to establish a value-based primary care capability specifically designed for Medicare patients, adding a critical clinical layer to its integrated healthcare model. Oak Street's differentiated approach — serving Medicare patients in underserved urban communities through a capitated, outcomes-focused primary care model — complemented Aetna's Medicare Advantage insurance operations and Caremark's pharmacy benefit management by providing the primary care coordination function that CVS had lacked. The acquisition was intended to demonstrate that CVS's integrated model could genuinely reduce total medical costs by keeping high-risk patients healthier through proactive primary care.
Impact
Oak Street Health gave CVS a clinical quality brand and a value-based care operating model that neither retail pharmacy nor insurance ownership had provided. The acquisition brought approximately 188 primary care centers and a patient panel of Medicare-eligible individuals, the majority enrolled in Medicare Advantage plans. Oak Street's clinical outcomes data — demonstrating lower hospitalization rates and higher patient satisfaction relative to comparable fee-for-service practices — gave CVS credible clinical evidence to support its integrated care value proposition in sales conversations with employer and government clients.
Outcome
As of 2025, Oak Street Health remains in investment mode — continuing to open new centers at a rate that generates near-term losses as patient panels mature and capitation payments ramp. The business is strategically validated but financially early-stage relative to CVS's other segments. Management has guided that Oak Street will become a meaningful earnings contributor as existing centers mature and new center economics improve. The critical test will be whether CVS can accelerate Oak Street's growth while maintaining the clinical quality that justified the acquisition premium.