This project is a collaborative effort to construct the first self- consistent computational model of a substorm by coupling the physics of the inner magnetosphere and the ionosphere (as represented by the Rice Convection Model) and the physics of the tail (as represented by the Los-Alamos/Goddard MHD model of tail dynamics). A third element is an equilibrium code that has been developed through a Los Alamos - Goddard - Rice collaboration. The fully merged Tail-MHD/RCM model is anticipated to be a powerful tool for testing substorm ideas for theoretical consistency and for making precise theoretical predictions that can be compared with observations. The project has evolved as part of the GEM effort to develop a modular Global Geospace General Circulation Model and consists of a prototypical coupling of a Core Module to a Tail/Substorm Module.