If unmitigated, disruption-generated runaway electrons (REs) could have individual energies of tens of MeV and together carry several MA of current in the SPARC tokamak. And while start-up REs are expected to be less energetic and numerous, it is still desired to avoid them. This talk presents an overview of recent progress in modeling of REs and their mitigation in SPARC. Start-up RE distribution functions have been studied by coupling STREAM and DREAM, and synthetic hard x-ray signals have been estimated for RE detection. Disruption RE generation and interactions with MHD as well as partially ionized impurities have been modeled with the nonlinear M3D-C1 code, including the effect of a RE mitigation coil (REMC); RE termination studies are also underway. Benchmarking with the kinetic DREAM code has also been performed. RE impacts with the first wall have been analyzed using the HEAT engineering code, and integration with GEANT is being pursued to simulate charged particle interactions and energy deposition. Geometric effects on such RE physics as the Compton source term and drift orbit losses are also considered. Finally, an update on RE mitigation in SPARC will be given, especially regarding the first campaign. This work is supported in part by Commonwealth Fusion Systems and the U.S. DoE FIRE Collaborative MiRACL under contract numbers DE-AC02-09CH11466 and DE-AC05-00OR22725. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy User Facility using NERSC award FES-ERCAP0035392.