Many types of computer software are currently available for the numerical modeling of monolithic RC structures; however, the accuracy of the numerical models created with the programs can only be acceptable by using a well-developed modeling method. We present the behavior of monolithic RC frame corners and beam to column joints for quasi-static and cyclic lateral loads, using numerical models created by our modeling method. Several laboratory experiments have already been carried out to investigate the failure of the joints and the behavior of these unique connections. In this paper, we made three-dimensional nonlinear FE body models with different reinforcement shapes, based on actual laboratory tests. We present the behavior of the joints in case of monotonic increasing quasi-static and cyclic changing loads. The results of laboratory experiments found in the literature and finite element calculations are compared and the conclusions that can be drawn from them are summarized within this article.