Efficiency improvement of the existing coal-fired power plants has been recognized as a path of no regret. The Affordable Clean Energy (ACE) rule issued on August 21, 2018, requires a 2.1% to 4.5% reduction in net plant heat rate and 1.5% improvement in net unit efficiency from each coal-fired power plant in the U.S. .The main objective of this study is the identification of cost-effective commercially-ready options, newly developed technologies, and concepts nearing commercial applications for improving efficiency for existing coal-fired power plants. The further objective is the analysis of performance improvement options and the quantification of achievable performance improvements. To accomplish the objective, system modeling and design analysis were performed by employing EBSILON Professional software (EPV-11). More specifically, the thesis goals include:• Comprehensive review and analysis of potential heat rate improvement.• Identification of practical cost-effective options for efficiency improvement and reduction of environmental compliance cost. • Quantification of efficiency improvement and cost for each of the selected performance improvement options.• Development and application of the methodology and analysis tools for determining the effects of identified performance improvement techniques.• Determination of cumulative performance improvements that could be achieved at two selected power plant designs (supercritical) firing high-rank and low-rank coals.