A bulk-current model for advanced metal oxide semiconductor field effect transistors (MOSFETs) is proposed and implemented. The model consists of an impact ionization mechanism, the drain to bulk current and a tunneling mechanism, the gate to bulk current, and requires totally 21 model parameters covering all bias conditions. The simulated results with the parameter values reproduce measurements for any device size without binning. Validity of the model has been tested with circuits, which are sensitive to the change of the stored charge due to impact ionization current and tunneling current. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.