Clinicians and hospital administrators rely on healthcare information systems (HIS) for decision- making. Typically, HIS need to aggregate data from a network of geographically dispersed healthcare facilities and specialized departments of medical practice. However interoperability issues in the data arise from the diversity of infrastructure, specialized practices, underlying systems, procedures and personnel in healthcare facilities. Silos of medical practice create both systemic and semantic interoperability issues. Using grounded theory, this research draws on interviews with HIS stakeholders in a large single provider nationalized healthcare network in the USA to formulate a model that explores how knowledge management practices coupled with technology can establish data interoperability standards. Additionally, increased knowledge sharing across the traditional silos of healthcare practices enhances the interoperability of patient data by supporting standards as well as data collection and abstraction procedures and processes.