One of the goals of the development of health information exchanges is to improve public health. In addition to improving the ability for clinicians to access health information on their patients, HIEs can also improve the efficiency of reportable disease investigations. Investigating reported diseases must be done in a timely manner and involves a great deal of effort to collect accurate and complete information. Multiple calls to laboratories and health care providers are made to verify patient demographic and clinical information. With the implementation of electronic health records systems in hospitals and clinics, disease investigators have been asked more and more to request clinical records from information management departments, further delaying the access to the records. Nebraska’s “official” HIE, the Nebraska Health Information Initiative (NeHII), was developed as a public-private collaborative and is run by a non-profit organization governed by a board. Security policies were initially set to only allow health care providers to access data on patients with whom they have a “treating relationship.” This prevented the HIE from allowing access for public health investigation. Security policies of the HIE had to be changed in order to allow public health access. Public health investigation use cases were developed to present to the privacy and security committee to explain public health agencies’ role in disease surveillance and control. Use cases were developed for disease investigation, tuberculosis case investigation and management, and infant mortality surveillance, which requires access to all infant and maternal medical records. In the future, more use cases may be developed for HIE access and will be presented to the privacy and security committee for approval. Educating the HIE about public health’s role in disease investigation was a key factor in gaining access. Using the HIE for disease investigation has tremendously improved the efficiency of public health investigators and has likely reduced the time health care providers spend responding to our requests.