An EHR is a digital version of a patient’s paper medical record or chart. EHRs ideally make information available instantly and securely to authorized users. An EHR can contain the medical and treatment history of a patient, diagnoses, medications, treatment plans, immunization dates, allergies, radiology images, and laboratory and test results. An EHR can also give a provider access to evidence-based tools for making decisions about a patient’s care and can automate certain workflows. EHR system software is typically purchased by providers (such as physicians, hospitals, and health systems) from vendors that develop the systems. When EHR systems are interoperable, information can be exchanged—sent from one provider to another—and then seamlessly integrated into the receiving provider’s EHR system, allowing the provider to use that health information to inform clinical care. HHS and others view EHR system interoperability as a necessary step toward transforming health care into a system that can achieve goals of improved quality, efficiency, and patient safety. For example, use of interoperable EHR systems could better enable health care providers to view results from diagnostic procedures conducted by other providers to avoid duplication; evaluate test results and treatment outcomes over time regardless of where the care was provided to better understand a patient’s medical history; share a basic set of patient information with specialists during referrals and receive updated information after the patient’s visit with the specialist to improve care coordination; view complete medication lists to reduce the chance of duplicate therapy, drug interactions, medication abuse, and other adverse drug events; and identify important information, such as allergies or preexisting conditions, for unfamiliar patients during emergency treatment to reduce the risk of adverse events. Health data standards are technical requirements used to, among other things, facilitate health information exchange and interoperability of systems, including EHR systems. Such standards consist of terminology and technical specifications that, when adopted by multiple entities, facilitate the exchange and interoperability of health information. Health data standards include, for example, standardized language for prescriptions and laboratory testing. Standards define how information is packaged and communicated from one entity to another, setting the language, structure, and data types required for integration between the systems. Standards generally have been developed by nonfederal standard development organizations and are accompanied by implementation guides, which can help ensure that standards are implemented uniformly. Consistent implementation of the standards by the vendors that build and sell EHR systems and by providers who use these systems is necessary for interoperability. The Medicare and Medicaid EHR Incentive Programs are intended to help increase the adoption and meaningful use of EHRs by providing incentive payments for providers—that is, certain hospitals and health care professionals such as physicians—who participate in Medicare and Medicaid, and later imposing payment adjustments, also referred to as penalties, on those Medicare providers that do not meet meaningful use requirements for a program year. Within HHS, ONC and the Centers for Medicare & Medicaid Services (CMS) develop the programs’ requirements. CMS establishes specific requirements providers must meet to qualify for incentive payments. Some of these requirements include the exchange of health information, which is a component of interoperability. ONC identifies health data standards and technical specifications for EHR systems and certifies EHR systems used by providers in the program to help ensure that providers implement a system that offers a minimum level of technological capability, functionality, and security. In order for an EHR system to be certified, it must adhere to requirements related to health information exchange, among other capabilities. The Health Insurance Portability and Accountability Act (HIPAA) of 1996 and its implementing regulations, the Privacy Rule, regulate covered providers’ use and disclosure of personal health information. Providers may also be subject to additional state privacy rules, which can be more stringent than HIPAA requirements or standards. For example, states can set requirements around default practices for health information exchange. Specifically, states that require patients to “opt-in” to health information exchange do not allow the sharing of health information unless patients affirmatively consent to share health information. States with “opt-out” policies around health information exchange permit, by default, the automatic sharing of patient health information, and patients must affirmatively express their preference to not have information shared if they do not want it exchanged. The initiatives we reviewed vary in their efforts to achieve or facilitate interoperability, including (1) the primary products or services they offer (e.g., a network or guidance for implementing standards), (2) the types of electronic systems the initiatives are working to make interoperable, (3) the cost of the initiatives’ products or services, (4) the geographic areas served by the initiatives, (5) the extent to which initiatives facilitate patient access to their health information, (6) the stakeholder groups that are members of the initiatives, and (7) the sources of funding for the initiatives. The majority of the initiatives we selected are works in progress, meaning that they are relatively new and therefore still in the process of developing, or encouraging others to adopt, their products or services. Of the 18 initiatives we selected, 10 began after January 2013. Representatives from 6 of the initiatives said that their primary products or services were available in some areas or available on a limited scale; however, according to the representatives, none of their products or services were widely available or widely used at the time of our review. For example, representatives from the 4 initiatives associated with HIE organizations said that they are actively facilitating interoperability, but this interoperability is confined to a single state or region. The 2 other initiatives have products available, but according to representatives, the initiatives are in the very early stages of deploying those products and anticipate that use of their products will increase by 2016. Representatives from 7 of the initiatives stated that their products or services are currently being developed and would not be available until the end of 2015 or sometime in 2016. Stakeholders and initiative representatives we interviewed described five key challenges to EHR interoperability, and initiative representatives described how they are working to address these challenges using different approaches. Initiative representatives also identified other issues beyond the scope of their initiatives that they say need to be addressed in order to move nationwide EHR interoperability forward. Stakeholders and representatives from the selected EHR initiatives described five key challenges to achieving EHR interoperability: (1) insufficiencies in standards for EHR interoperability, (2) variation in state privacy rules, (3) accurately matching patients’ health records, (4) costs associated with interoperability, and (5) need for governance and trust among entities. While standards for electronically exchanging information among EHR systems exist, stakeholders and initiative representatives said that these standards are not sufficient for achieving EHR interoperability. This challenge stems from the fact that some standards are not specific enough and, as a result, the systems that implement these standards may not be interoperable. According to some stakeholders, some standards allow EHR systems to use different formats and terminology when exchanging data. However, this resulting variability prevents the receiving system from processing the information and properly integrating it into the patient record; in other words, the systems are not interoperable. Information that is electronically exchanged from one provider to another must adhere to the same standards, and these standards must be implemented uniformly, in order for the information to be interpreted and used in EHRs, thereby enabling interoperability. Stakeholders and initiative representatives said that exchanging health information with providers in other states, which is necessary for nationwide EHR interoperability, can be difficult. This challenge exists because of variations in privacy rules from state to state, especially variation in laws pertaining to patient consent for sharing health information. According to a representative from one initiative, providers in opt-in states may be hesitant to exchange health information with providers in opt-out states if the providers lack assurance that the patients have explicitly consented to the exchange. This challenge may be more pronounced when exchanging certain types of sensitive information, such as mental health information or HIV status, among providers in different states. Some states require additional patient consent when exchanging such information. A representative from one initiative explained that current digital methods for exchange do not provide assurance that sensitive information is protected in accordance with privacy rules. According to this initiative representative, the sensitive information that is subject to more stringent privacy rules could be inadvertently aggregated with other health information and exchanged without the patient’s consent, thereby violating privacy rules. Representatives from one initiative noted that they specifically do not include any mental health information in electronic health information exchange, even with patient consent, because of concerns about inadvertently violating privacy rules. Stakeholders and initiative representatives said that another key challenge to EHR interoperability is accurately matching patients’ health records that are stored in different systems. This challenge exists because many EHR systems use demographic information, such as a patient’s name and date of birth, to match different health records for a given patient held by different providers. As we previously reported, demographic variables do not always yield accurate results because, for example, there could be more than one patient with the same information. In addition, providers may not collect and use the same demographic variables for matching. For example, one initiative representative explained that a recent effort to achieve interoperability with another organization stalled because the other organization relies on a patient’s social security number for patient matching, but the initiative does not collect social security numbers for its patients. In addition, some methods to match records for the same patient across providers can fail because of differences across EHR systems in data formats or because of missing data from or inaccurate data in some health records. Stakeholders and initiative representatives said that the costs associated with achieving interoperability can be prohibitive for providers. This challenge exists in part because of the high cost of EHR customization and legal fees associated with interoperability.