We extend our previously suggested drift-diffusion (DD)-based hot-carrier degradation model to the case of decananometer transistors. Special attention is paid to the effect of electron–electron scattering, which populates the high energy tail of the carrier distribution function, by using a rate balance equation. We compare the results of the DD-based model with the results obtained from a spherical harmonics expansion of the Boltzmann transport equation as well as experimental data. We also study the accuracy and limits of the applicability of the DD-based model and conclude that this model is able to capture hot-carrier degradation in nMOSFETs over a range of gate lengths from 65 to 300 nm with excellent accuracy.