It is well-known that water management plays a critical role in operation of PEM fuel cells especially under the dynamic operating conditions and relatively low temperatures, in which both liquid and gaseous water is present. In this study, the wettability of the cathode catalyst layer (CL) on MEAs is characterized by ex-situ sessile-drop method. The method was applied on ten cathode CLs with varying carbon loss (0 to 13 wt% of the cathode) under both potential cycling and holds. The apparent contact angles of the cathode CL decreased from 143.5° to 130° after severe corrosions. Atomic Force Microscopy and X-ray Photoelectron Spectroscopy were used to elucidate structural and compositional changes that account for the decrease in apparent contact angles.