© 2016 IEEE. This paper reviews the major developments in thin-film transistor (TFT) modeling for the computer aided design (CAD) and simulation of circuits and systems. Following the progress in recent years on oxide TFTs, we have successfully developed a Verilog-AMS model called the CAMCAS model, which supports computer aided circuit simulation of oxide-TFTs, with the potential to be extended to other types of TFT technology families. Also reviewed are the features of SPICE and Verilog-AMS models and their comparison in terms of development complexity and execution speed. This is aimed at providing a guideline for researchers in the CAD area while enabling the choice of platform to implement their models.