The purpose of the present research is to review the Applied Element Method (AEM) formulation and its implementation in the commercial software Extreme Loading for Structures (ELS) to study the progressive collapse of R.C frames [1]. Also, the properties and capacities of (ELS) used to simulate and describe the progressive collapse events. This paper focuses on the progressive collapse of 2-D and 3-D reinforced concrete frames, provides a validation for (AEM) using (ELS) by simulating and modeling four reinforced concrete frames tested experimentally in laboratories by other researchers. To verify (ELS), the frames are modeled numerically using (ELS) with the same loading technique, concrete dimensions and reinforcement details of the tested frames, then the results are compared with the experimental results to validate AEM. A 2-D three-story frame is modeled with interior column removal study. The second validated frame was a 2-D two-story frame with interior column removal. The third validated specimen was a 3-D single-story frame with corner column removal. Also a 3-D three-story frame is modeled with central edge column removal. The 3-D frames are studied taken into consideration the contribution of slabs to determine the effect of different structural elements in progressive collapse. Crack pattern, deformed shape, load deformation curve, concrete strains and steel strains are obtained from numerical models and are compared with the experimental results. Generally, the numerical results are in a good agreement with experimental ones.