This project developed methods and measures that can be used to quantify the public benefits that result from Interoperable Health Information Exchange (IEHI). In the first phase of this project, we conducted a literature review and discussions with subject matter experts to identify areas where evidence suggests that the greatest benefits resulting from IEHI might be found. Overall, we found that the current empirical evidence on the public benefits associated with IEHI is limited. Most recent studies had limited ability to make causal inferences because of the lack of pre-IEHI baseline information, lack of a comparison group showing results where there was no IEHI, and lack of information on whether IEHI data was being used. In the second phase, we developed a use case approach to identify measures that can be used to fill gaps in the literature and demonstrate the public benefits associated with IEHI, while avoiding some methodological challenges. The use case approach also considers the evolving nature of the technology and how to better quantify the process and intermediate outcomes that are part of the causal link between IEHI and public benefits. The three use cases selected were (1) alert, discharge, and transfer (ADT) event notifications to reduce unnecessary health care utilization through improved communication between providers and patients; (2) medication reconciliation to reduce adverse drug events during care transitions through reduced medication discrepancies; and (3) closing the referral loop to improve safety and efficiency through better care coordination between primary care and specialist providers.