There has been remarkable progress in development and implementation of electronic medical records (EMR), laboratory information systems (LIS), and logistics management information systems (LMIS) in resource-limited settings. However, the siloed nature of many implementations means there is tremendous untapped potential within existing tools. Achieving interoperability of open-source data systems has potential to boost efficiency and quality of front-line clinical services where these systems are used. This session will focus on practical considerations in designing and implementing interoperability between leading open-source EMR (i.e. OpenMRS), LIS (i.e. OpenELIS), and LMIS (i.e. OpenLMIS) data systems, based on the OpenHIE framework. In response to growing need for laboratory and clinical systems integration in Haiti, the International Training and Education Center for Health (I-TECH) and the Digital Initiatives Group at I-TECH (DIGI) developed a stand-alone module using HL7 and LOINC to communicate lab results directly from the national public health laboratory's system, OpenELIS, to the national OpenMRS-based EMR. Increased demand for comparable integration globally has led to the need for easily applicable, open-source solutions. Panelists from I-TECH/DIGI, the OpenMRS community, and the OpenLMIS community will describe practical designs and generalizable approaches for achieving interoperability between these data systems. First, panelists will describe the process for creating a generalizable solution for OpenMRS-OpenELIS interoperability, including adaptation, leveraging of existing architecture, and successful collaboration with robust developer and domain communities. The session will detail the growth of FHIR as a standard for data exchange and explore the integration of a FHIR-based API into OpenELIS. Next, panelists will share use cases for OpenELIS-OpenLMIS integration and outline the steps to carry out this integration. Finally, the session will frame the way forward for implementing the leading open-source clinical information systems OpenELIS, OpenMRS, and OpenLMIS as interconnected data systems within national or sub-national health information system architectures.