Horizontal and Vertical Integration of Health Care Providers: A Framework for Understanding Various Provider Organizational Structures

INTRODUCTION: Current U.S. policy and payment initiatives aim to encourage health care provider accountability for population health and higher value care, resulting in efforts to integrate providers along the continuum. Providers work together through diverse organizational structures, yet evidence is limited regarding how to best organize the delivery system to achieve higher value care. METHODS: In 2016, we conducted a narrative review of 10 years of literature to identify definitional components of key organizational structures in the United States. A clear accounting of common organizational structures is foundational for understanding the system attributes that are associated with higher value care. RESULTS: We distinguish between structures characterized by the horizontal integration of providers delivering similar services and the vertical integration of providers fulfilling different functions along the care continuum. We characterize these structures in terms of their origins, included providers and services, care management functions, and governance. CONCLUSIONS AND DISCUSSION: Increasingly, U.S. policymakers seek to promote provider integration and coordination. Emerging evidence suggests that organizational structures, composition, and other characteristics influence cost and quality performance. Given current efforts to reform the U.S. delivery system, future research should seek to systematically examine the role of organizational structure in cost and quality outcomes.