Across the United States, federal, state, and private efforts are under way to promote accountable care systems that encourage higher-quality care, control costs, and improve population health. A new set of Commonwealth Fund case studies looks at how three diverse organizations—Health Share of Oregon, Hill Physicians Medical Group, and Marshfield Clinic—came to develop accountable care systems for their patients covered by Medicare, Medicaid, and commercial health plans. An accompanying report, The Road to Accountable Care: Building Systems for Population Health Management, synthesizes findings from all three cases and offers lessons to help health care leaders considering similar initiatives.