A multi-year effort has examined high-temperature corrosion issues for current and future coal-fired boilers. On the fireside, there was concern that higher levels of CO<Sub>2</SUB>, H<Sub>2</SUB>O and SO<Sub>2</SUB> in the recirculated flue gas of oxy-fired systems would accelerate corrosion rates, particularly for Ni-base alloys at 700°-800°C. Evaluation of commercial and model alloys using synthetic ash and representative gas mixtures indicated little effect of these changes. On the steamside, there is no concern about the steam oxidation resistance of cast or wrought Ni-base alloys up to 800°C and no increase in oxide thickness or internal oxidation in steam compared to air. Shot peening of austenitic type 304 stainless steel tubing is highly effective in reducing the oxidation rate in 1 bar steam at 600°-650°C. However, at 650°C, the benefit begins to breakdown after 5,000 h. Research supported by the U.S. Department of Energy, Office of Fossil Energy, Crosscutting Research Program.