The recent surge in cloud computing arises from its ability to provide software, infrastructure, and platform services without requiring large investments or expenses to manage and operate them. Clouds typically involve service providers, infrastructure/resource providers, and service users (or clients). They include applications delivered as services, as well as the hardware and software systems providing these services. Cloud computing characteristics include a ubiquitous (network-based) access channel; resource pooling; multitenancy; automatic and elastic provisioning and release of computing capabilities; and metering of resource usage (typically on a pay-per-use basis). Virtualization of resources such as processors, network, memory, and storage ensures scalability and high availability of computing capabilities. Clouds can dynamically provision these virtual resources to hosted applications or to clients that use them to develop their own applications or to store data. Rapid provisioning and dynamic reconfiguration of resources help cope with variable demand and ensure optimum resource utilization. cloud-based electronic medical record (EMR) management systems like Practice Fusion, Verizon Health Information Exchange, Medscribbler, and GE Healthcare Centricity Advance are emerging. In addition, government agencies are working toward building interoperable healthcare information systems that promote electronic exchange of data across multiple organizations. These developments will influence healthcare providers to interact with multiple cloud-based EMR systems in the future. cloud mashups require preestablished agreements among providers as well as the use of custom-built, proprietary tools that combine services through low-level, tightly controlled and constraining integration techniques. This approach to building new collaborative services does not support agility, flexibility, and openness.