Wide bandgap (WBG) semiconductor devices represent an attractive developing technology for power applications that is recently gaining commercial ground. GaN has advantages as one of the top contenders with high bandgap, high mobility, high saturation velocity, and high breakdown voltage. GaN enhancement-mode devices are favored over depletion-mode devices for power electronics applications and are only recently becoming commercially available. The enhancement-mode device investigated in this work is a GaN-gate injection transistor (GIT) in which the normally-off operation is achieved with an additional p-doped gate. This paper presents current-voltage (I-V) characteristics of GaN-GIT device using a physics based compact model as well as TCAD (Technology Computer-Aided Design) numerical simulation to predict and model the device behavior of the GIT. This paper presents a comparison of the TCAD simulation results with a compact model intended for low frequency applications in power electronics in the KHz to MHz range.