Understanding the benefits of electronic prescribing systems has important implications for quality and efficiency in medical care. We surveyed physicians about their use of e-prescribing in outpatient practices. We found that physicians who use e-prescribing systems integrated into an electronic health record have different characteristics, usage patterns, perceived benefits, and levels of satisfaction than physicians who use stand-alone systems. For example, although only 56 percent of the physicians we surveyed said that they checked a patient’s drug history most or all of the time when writing a prescription, those with integrated systems were significantly more likely to report doing so than their counterparts with stand-alone systems. Our findings have implications for the American Recovery and Reinvestment Act’s requirements for e-prescribing and the future use of this technology. Because many stand-alone systems cannot meet meaningful-use requirements, there is likely to be a shift toward integrated systems