Telemedicine is the use of telecommunications technology for medical diagnostic, monitoring, and therapeutic purposes where distance and/or time separates the patient and health care provider. Both federal and private health insurers are now covering some telemedicine services, despite the fact that the benefits and costs of providing many of these services have not been well studied. This report assesses the peer-reviewed literature of specific telemedicine study areas, with a focus on those that substitute for face-to-face medical diagnosis and treatment of the Medicare population. Thus, this report targets face-to-face clinical specialties (as opposed to radiology and pathology) and the Medicare population. It does not evaluate studies examining populations that usually are not covered by Medicare, such as children and pregnant women. The report identifies health care services that could be provided using telemedicine and describes existing programs in three categories of telemedicine: store-and-forward, home-based and office/hospital-based services. This evidence report provides an update on the state of telemedicine, following the 2001 publication of Telemedicine for the Medicare Population. It identifies whether there has been significant progress in the number and types of telemedicine studies being conducted. More specifically, we searched for well-designed studies that evaluated telemedicine services in three technological categories described below.