Of the many factors that contribute to poor medication adherence among the chronically ill, the portion of drug costs borne by patients appears to be central. Pitney Bowes is one of a handful of large employers and insurers that have begun experimenting with reduced copays for essential medications. In 2007, the company reduced or eliminated cost-sharing for medications used to treat coronary artery disease and osteoporosis, with the goal of improving employees' medication adherence and health outcomes. This project will examine Pitney Bowes claims data to determine the impact that reduced copayments have had on medication adherence, clinical outcomes, health care utilization, and costs. The findings will aid employers, private insurers, the Medicare program, and policymakers in crafting changes to the structure of health benefits that lead to increased use of prescription drugs known to be effective for managing chronic disease.