Driven by widespread interest in improving health care quality and reducing costs and by the Affordable Care Act’s "accountable care" provisions, shared-savings programs are gaining traction as an alternative approach to paying health care providers. Providers receive a share of the savings they achieve by reducing the growth in costs for delivering care to a defined patient population. This report presents six case studies of pilot shared-savings programs across the country. The cases reveal program variation in the patient populations subject to shared-savings approaches, the health care services covered, the determination of cost savings and payouts to providers, the use of performance targets, and performance measurement. Early results from the pilot programs also vary. Exploring differences in shared-savings approaches, and the outcomes they achieve, will be essential to determining whether they work, how to improve them, and whether and how to diffuse them.