A fleet of 91 residential-scale proton exchange membrane (PEM) fuel cells, ranging in size from 1 to 5 kW, was demonstrated at various U.S. federal facilities worldwide. This detailed analysis looks into the most prevalent means of failure in the PEM fuel cell systems as categorized from the stack, reformer, and power conditioning systems as well as the subsequent subsystems. Also evaluated are the lifespan and failure modes of selected fuel cell components, based on component type, age, and usage. The balance of plant, with the numerous pumps and filters, accounted for 60.6% of the total component outages, followed by the fuel cell stack system (20.4%), fuel processing system (10.7%), and the power conditioning system (8.2%). Hydrogen cartridges were the most prevalent component replaced (79), but various filters (RO, DI, air-intake, carbon) account for almost 25% (175) of the total component outages. The natural gas fuel cell stacks had the highest average operational lifetime; one stack reached a total of 10,250 h.