The PBI/phosphoric acid fuel cell is a medium temperature PEM, typically operating at 175C. It has distinct advantages over Nafion fuel cells, such as low cost, high CO tolerance, and requires no humidification. PBI/phosphoric acid MEA fabrication and use will be compared to Nafion and sulfonated styrene-ethylene (SSE) MEAs. The chemistry and operating characteristics of PBI fuel cells will be discussed in detail. Two working reformed methanol fuel cell systems using PBI fuel cells will be demonstrated and available for examination.