This report frames the opportunities for efficiency improvements to coal-fired power plants (CFPPs) assuming the lower-performing CFPPs in each online-year group ought to be able to do as well as the better performing plants. Later sections of the paper show that, aside from a unit’s age and steam cycle type, plant attributes such as location and emissions control equipment do not account for variation in efficiency; this indicates operational practices and maintenance play large roles in determining the efficiency of a unit and suggests that improvements are possible.