In this paper, two testing protocols were developed in order to accelerate the lifetime testing of proton exchange membrane (PEM) fuel cells. The first protocol was to operate the fuel cell at extremely high temperatures, such as 300 °C, and the second was to operate the fuel cell at unusually high current densities, such as 2.0 A/cm2 . A PEM fuel cell assembled with a PBI membrane-based MEA was designed and constructed to validate the first testing protocol. After several hours of high temperature operation, the degraded MEA and catalyst layers were analyzed using SEM, XRD, and TEM. A fuel cell assembled with a Nafion 211 membrane-based MEA was employed to validate the second protocol. The results obtained at high temperature and at high load demonstrated that operating a PEM fuel cell under certain extremely high-stress conditions could be used as methods for accelerated lifetime testing.