MPAS-JEDI is a multi-component software package that provides everything that is needed to run data assimilation applications for the atmospheric core of the Model for Prediction Across Scales (MPAS). The National Center for Atmospheric Research (NCAR) and the Joint Effort for Data assimilation Integration (JEDI) core team at the Joint Center for Satellite Data Assimilation (JCSDA) jointly develop MPAS-JEDI. The software and associated documentation are officially released on github and accessible from https://www.jcsda.org/jedi-mpas. JEDI is a development project led by JCSDA. The purpose of JEDI is to provide a comprehensive generic data assimilation framework that will accelerate data assimilation developments and the uptake of new observation platforms for the community. MPAS is a collaborative project for developing atmosphere, ocean and other earth-system simulation components for use in climate, regional climate and weather studies, whose primary development partners are Los Alamos National Laboratory and NCAR. MPAS-JEDI employs MPAS’s native meshes, including regional and variable-resolution meshes, and performs I/O with native MPAS-A files.