Abstract This paper presents a new degraded drain current model for nMOSFETs with hot-carrier-induced interface states. The model was developed by starting from a two-dimensional Poisson's equation and including the effects of series resistances, carrier velocity saturation, and hot-carrier-induced interface states. The nonuniform spatial distribution of interface states is also accounted for in the model. The fitting results show good agreement between the model and the experimental data. The model provides a physics-based approach for modeling forward and reverse MOSFET characteristics with hot-carrier-induced damage and can be easily applied to simulation of device behavior after hot-carrier stress for assessment and improvement of long-term device or circuit reliability.