Accurate performance prediction of SiC MOSFETs using TCAD necessitates models for both impact ionization coefficients and mobility at SiC MOS interfaces; the former has been previously reported by us. However, a standardized mobility model for SiC MOS interfaces has not yet been established due to the complex physics inherent to SiC MOS interfaces. To address this gap, we have developed a physically grounded and reliable mobility model for SiC MOSFETs in TCAD, which is applicable under a wide range of experimental conditions. This model is derived from our comprehensive investigations into the physics that govern mobility at SiC MOS interfaces, including the energy distribution of interface traps near the conduction band and the elucidation of the dominant scattering mechanisms affecting mobility.