soilice is an open-source, python-based coupled heat and mass transport model for simulating hydrological processes in frozen soils. The model has excellent mass and energy conservation, including for problems with significant mass flow and advected heat. The code is simple and readable, making it easy to test new algorithms and process representations. In this presentation we show how soilice is able to simulate infiltration in seasonally frozen soils in a way that is consistent with the field-based conceptual understanding of infiltration processes, where snowpack and antecedent soil moisture play a critical role in runoff vs infiltration partitioning. We use the model to show the critical importance of frozen-soil hydraulic conductivity in simulating snowmelt infiltration and moisture redistribution by cryosuction. We apply the model to both seasonally frozen and permafrost soils, and demonstrate the importance of accurately representing infiltration in frozen soils for realistic simulations of soil moisture and freeze-thaw dynamics in cold regions.