Patient-centered, accountable care has garnered increased attention with the passage of the Affordable Care Act and new Medicare regulations. This case study examines a care model jointly developed by a provider and a payer that approximates an accountable care organization for a Medicare Advantage population. The collaboration between Aetna and NovaHealth, an independent physician association based in Portland, Maine, focused on shared data, financial incentives, and care management to improve health outcomes for approximately 750 Medicare Advantage members. The patient population in the pilot program had 50 percent fewer hospital days per 1,000 patients, 45 percent fewer admissions, and 56 percent fewer readmissions than statewide unmanaged Medicare populations. NovaHealth's total per member per month costs across all cost categories for its Aetna Medicare Advantage members were 16.5 percent to 33 percent lower than costs for members not in this provider organization. Clinical quality metrics for diabetes, ischémie vascular disease, annual office visits, and postdischarge follow- up for patients in the program were consistently high. The experience of developing and implementing this collaborative care model suggests that several components are key, including robust data sharing and information systems that support it, analytical support, care management and coordination, and joint strategic planning with close provider-payer collaboration. [ABSTRACT FROM AUTHOR]