In this paper, we report our ongoing team efforts (which are being funded by the US Department of Energy) toward the development and validation of a three-dimensional, two-phase, comprehensive PEM (polymer electrolyte membrane) fuel cell model. Specifically, we report our progress in following areas: i) a channel two-phase flow submodel to account for the presence of liquid water in flow channels and its effect; ii) an approximate but robust approach for taking MPL (microporous layer) effect into account; iii) an investigation into the effect of cell segmenting; and iv) an ongoing effort in model validation.Copyright © 2011 by ASME