Purpose: The purpose of this study was to identify the organizational factors that influence electronic health information exchange (HIE) by medical group practices in rural areas. Methods: A purposive sample of 8 small medical group practices in 3 experimental HIE regions were interviewed to determine the extent of clinical information exchange with other health care providers and to identify the factors influencing those patterns. Findings: HIE was found to be largely limited to exchanging immunization data through the state health department and exchanging clinical information within owned provider systems. None of the clinics directly exchange clinical information with non-owned clinics or hospitals. Conclusions: While regional HIE networks may be a laudable goal, progress is slow and significant technical, political, and financial obstacles remain. Limiting factors include data protection concerns, competition among providers, costs, and lack of compatible electronic health record (EHR) systems.