MPAS-Seaice is a new sea ice model that uses a Voronoi tesselation grid to allow variable resolution. It uses the same EVP rheology, horizontal variational operators and incremental remppaing for transport as CICE but adapted for arbitrarily shaped polygonal cells. It uses the same column package library as CICE for column physics (vertical thermodynamics, shortwave radiation, mechanical redistribution) and biogeochemistry.