This research report, prepared by Ian Wright and HH Krause for the National Renewable Energy Lab under the direction of the ASME CENTER for Research and Technology Development, was conducted to assess the overall significance of the major factors affecting the boiler tube lifetime in waste fired steam generators and to identify the research needs and opportunities that could have the greatest impact on the metal wastage problem. Data was compiled from open literature and available reports, and supplemented with the expertise and operating experience and erosion/corrosion problems encountered by owners, operators, and manufacturers. Topics discussed include: Trends in Waste-Derived Fuel. Summary of Current Understanding of the Causes of Metal Wastage in MSW Combustors. Overview of Metal Wastage Experienced in Waste- Fired Steam Generators. Economic Impact of Boiler Tube Problems in Waste-Fired Boilers. Research Opportunities. Sources, Methodology & Questionnaire Used, Listing of Waste-to-Energy Units.