The document discusses the mission and agenda of the ISPOR Special Interest Group (SIG) on open-source models related to cost-effectiveness studies, highlighting the importance of transparency and collaboration in advancing health economics. It outlines the goals, rationale, and priority areas for the SIG, emphasizing the need for accurate and accessible models to support healthcare decision-making. The agenda includes presentations from experts and discussions on the implications of open-source models in healthcare policy and reimbursement.