The efficiency of conventional boiler/steam turbine fossil power plants is a strong function of steam temperature and pressure. Since the energy crisis of the 1970s, research to increase both has been pursued worldwide. The need to reduce carbon monoxide emissions has provided further incentive to improve efficiency. The main enabling technology is the development of stronger high temperature materials. EPRI has recently comleted a state-of-the-art review of materials technology for ultra supercritical power plants. This review will serve as a basis for defining material issues for both the boiler and the turbine in next generation ultra supercritical power plants.