The accountable care organization (ACO) concept is advocated as a promising value-based payment model that could successfully realign the current payment system to financially reward improvements in quality and efficiency. Focusing on the care of hospitalized patients and controlling a substantive portion of variable hospital expenses, hospitalists are poised to play an essential role in system-level transformational change to achieve clinical integration. Especially through hospital and health system quality improvement (QI) initiatives, hospitalists can directly impact and share accountability for measures ranging from care coordination to implementation of evidence-based care and the patient and family caregiver experience. Regardless of political terrain, financial constraints in healthcare will foster continued efforts to promote formation of ACOs that aim to deliver coordinated, evidence-based, and patient-centered care. Hospitalists possess the clinical experience of caring for complex patients with multiple comorbidities and the QI skills needed to lead efforts in this new ACO era.