Few U.S. hospitals have implemented computerized physician order entry (CPOE) in spite of its effectiveness at preventing serious medication errors. We interviewed senior management at twenty-six hospitals to identify ways to overcome barriers to adopting and implementing CPOE. Within the hospital, strong leadership and high-quality technology were critical. Hospitals that placed a high priority on patient safety could more easily justify the cost of CPOE. Outside the hospital, financial incentives and public pressures encouraged CPOE adoption. Dissemination of data standards would accelerate the maturation of vendors and lower CPOE costs. These findings highlight several policy levers to speed the adoption of this important patient safety technology.