In this paper, we report the anomalous behavior of capacitances in halo channel MOSFET for the linear and saturation regions. Unlike MOSFETs these devices have different threshold voltage (VTH) for the DC and CV operations, and therefore cannot be modeled by conventional methods. We have investigated various cases of doping non-uniformity: Source side halo (SH), Drain side halo (DH), both side halos (Halo) and uniformly doped (UD) transistors using TCAD simulations under various bias conditions. A computationally efficient SPICE model is used to model these trends which shows excellent matching with the measured and TCAD data.