Compared to alkaline electrolyzers, PEM electrolyzers offer high current densities and can be coupled to renewable energy sources because of their fast responses to dynamics. The modeling of PEM electrolyzers is a challenging issue to reproduce its behavior and to design properly power electronics and its control without damaging a real electrolyzer. The input current may have an impact on the dynamics of the electrolyzer and must be taken into consideration to make a model more reliable. In this work, an equivalent electrical circuit to replicate accurately the dynamic behavior of the PEM electrolyzer subject to fast current change is investigated. Based on the input current, the parameters of the model can not be considered as constant. Hence, to improve the accuracy of the model, an adaptive staticdynamic electrical model is proposed and takes into consideration the change of input current. This model is validated by using a commercial-400 W PEM electrolyzer. The obtained results demonstrate the effectiveness of the model to predict the PEM stack voltage. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.