As the linear dimensions of a MOSFET are reduced to the sub-0.1μm range, the Bias Temperature Instability (BTI), Hot-Carrier Injection (HCI) and the Time-dependent Dielectric Breakdown (TDDB) become very crucial reliability concerns. Due to the drastic increase of the electric field in the channel of modern MOSFETs, carriers are heated and then gain sufficient energy to produce damage in an insulator film. From a microscopic point of view, BTI and HCI are closely linked, however it has been repeatedly reported in the literature that HCI-induced degradation has a larger permanent component. This circumstance suggests that another additional (with respect to BTI) mechanism contributes to the HCI-related damage. One may conditionally separate the hot carrier reliability modeling into two main sections. The first is related to the energetics of the Si-O, Si-H and Si-Si bond-breakage, while the second is devoted to the calculation of the non-equilibrium distribution function of the carriers in the channel. Because of the great impact contributed by the heated particles to the degradation process, the high-energetical tails of the energy distribution should be carefully modeled. In this connection the full-band device Monte-Carlo method is very well suited. Such an approach allows us not only to model the distribution function but also to calculate such relevant parameters as the carrier dynamic temperature, velocity, electrical field distribution, etc. for real (i.e. industrial) MOSFETs.