HealthPartners is the nation's largest nonprofit, consumer-governed health care organization, providing health and dental care and coverage to more than 1 million individuals in Minnesota and surrounding states. Key factors driving HealthPartners' performance are a consumer-focused mission; a regional focus, scale, and scope integrating a broad range of services; strategic use of electronic health records to support care redesign; and a culture of continuous improvement. A comprehensive model for improvement includes setting ambitious targets for health system transformation; measuring what is important in order to optimize care; agreeing on best care practices and supporting improvement at the clinic level; aligning incentives with goals; and making results transparent internally and externally. HealthPartners' experience suggests that a nonprofit health plan market oriented to physician group practice--supported by collaborative measurement, improvement, and reporting structures--creates a community environment that helps each participant achieve objectives more effectively.