Healthcare providers increasingly use mobile devices to receive, store, process, and transmit patient clinical information. According to our own risk analysis, discussed here, and in the experience of many healthcare providers, mobile devices can introduce vulnerabilities in a healthcare organization’s networks. At the 2012 HHS Mobile Devices Roundtable, participants stressed that many providers are using mobile devices for healthcare delivery before they have implemented safeguards for privacy and security. This NIST Cybersecurity Practice Guide provides a modular, open, end-to-end reference design that can be tailored and implemented by healthcare organizations of varying sizes and information technology (IT) sophistication. Specifically, the guide shows how healthcare providers, using open-source and commercially available tools and technologies that are consistent with cybersecurity standards, can more securely share patient information among caregivers who are using mobile devices. The scenario considered is that of a hypothetical primary care physician using her mobile device to perform recurring activities such as sending a referral (e.g., clinical information) to another physician, or sending an electronic prescription to a pharmacy. While the design was demonstrated with a certain suite of products, the guide does not endorse these products in particular. Instead, it presents the characteristics and capabilities that an organization’s security experts can use to identify similar standards-based products that can be integrated quickly and cost-effectively with a healthcare provider’s existing tools and infrastructure.