INTRODUCTION: Medical conditions occurring in spaceflight pose risks to the crew and the mission and these risks will be exacerbated during exploration-class missions. Probabilistic risk assessment is a method used at NASA to quantify this risk for low-Earth orbit operations. Informing Mission Planning via Analysis of Complex Tradespaces (IMPACT) is a next-generation tool suite that will perform these assessments for exploration-class missions. It will require a robust list of medical conditions of significant likelihood and/or consequence to exploration-class missions to accurately inform the tool suite.METHODS: The IMPACT 1.0 Medical Condition List (ICL 1.0) contains 120 conditions selected in the context of a 210-d cis-lunar, Mars analog design reference mission. The conditions were selected via a systematic process that preserved institutional knowledge from nine prior condition lists. Conditions were prioritized for inclusion in the ICL 1.0 based on history of occurrence in spaceflight, concurrence among the nine source lists, and concurrence among subject matter experts.DISCUSSION: The ICL 1.0 has notable advantages over its predecessor lists in that it is more specific to exploration-class missions, contains a greater number, breadth, and depth of conditions, and was derived via consensus across multiple medical specialties.Kreykes AJ, Suresh R, Levin D, Hilmers DC. Selecting medical conditions relevant to exploration spaceflight to create the IMPACT 1.0 Medical Condition List. Aerosp Med Hum Perform. 2023; 94(7):550-557.