Precise modeling of the saturation velocity is a key element for device simulation, especially for advanced devices such as e.g. High Electron Mobility Transistors (HEMTs) where the saturation velocity v sat is directly related to the available gain of the device. We present a model implementing the temperature dependence of the saturation velocity v sat into the two-dimensional device simulator MINIMOS-NT. The new model covers all relevant materials such as the elementary semiconductors Si and Ge, and the binary III-V group semiconductors GaAs, AlAs, InAs, GaP and InP. Furthermore, a composition dependent modeling for alloyed semiconductors such as e.g. Si 1รx Ge x , Al x Ga 1รx As or In x Ga 1รx As is included. The implementation reยฏects a comprehensive literature survey on available experimental data and Monte Carlo (MC) simulation data. The work is completed by new MC simulations, especially for material compositions, where no experimental data are available. The extraction of the saturation velocity reveals a signiยฎcant dierence between the saturation velocity in the bulk and the eective (saturation) velocity extracted from rf-measurements e.g. for High Electron Mobility Transistors. Since this eective value is often used for device characterization, the dierence gives insight into modeling the determining quantities of HEMTs.