In this paper, RF modeling and step-by-step parameter extraction methodology of the BSIM-IMG model are discussed with experimental data. BSIM-IMG is the latest industry standard surface potential based model for fully depleted siliconon-insulator (FDSOI) transistors. The impact of gate, substrate, and thermal networks is demonstrated with S-parameter data, which enable the BSIM-IMG model to capture RF behavior of the FDSOI transistor. The model is validated over a wide range of biases and frequencies and excellent agreement with the experimental data is obtained.Index Terms-BSIM-IMG, compact model, fully depleted silicon-on-insulator (FDSOI), MOSFET, parameter extraction, RF.