In previous practices, the computation and distribution of seismic base shear forces throughout the height of structures predominantly relied on the elastic design (ED) method as outlined in various structural codes. This approach often resulted in designs that were neither optimal nor cost-effective, potentially leading to severe damage to buildings during seismic events. To address these shortcomings, the Performance-Based Plastic Design (PBPD) method has emerged in recent years, emphasizing the plastic behavior of structures. This study focuses on assessing the seismic collapse capacity of steel moment resisting frames (SMRFs) designed using both the ED and PBPD methods. Two SMRFs, comprising five and ten stories with intermediate ductility, were analyzed using OpenSees software, subjected to seven pairs of far-fault earthquake records. Subsequently, incremental dynamic analysis (IDA) was conducted until structural failure occurred, allowing for the extraction of fragility curves to evaluate the seismic collapse capacities of the frames. The findings indicate that the PBPD method enhances the control over yield mechanisms and the plastic deformation capacity of structures. Furthermore, the probability of failure for frames designed with the PBPD method is deemed acceptable. Notably, the research reveals that the seismic collapse capacities of frames designed with PBPD are significantly superior to those designed with ED, with a 25% and 31% increase in collapse capacity for the five-story and ten-story frames, respectively, at a statistical level of 50%. This underscores the reliability and precision of the PBPD method in comparison to the ED approach.