Cloud computing, financial incentive and patient-centered care are the game changers that deepen EHR diffusion beyond breadth. Based on the innovation diffusion theory (IDT), technology-organization-environment (TOE) framework and alignment literature, this study examines how these changes shape business requirement, service value and society need that drive different phases of EHR diffusion in terms of planning, adoption, usage and upgrade. A longitudinal analysis with the USA National Ambulatory Medical Care Survey (NAMCS) reveals the impacts of different drivers on EHR diffusion. In addition to quantitative results, interview observations corroborate the relationships among game changers, decision drivers and EHR diffusion. The findings provide healthcare providers, system vendors and policy-makers the insights on the best practices of promoting EHR diffusion for long-term success
