As gas turbine engine designers strive to increase engine efficiency, thrust, and higher turbine inlet temperatures, the substrate superalloys are pushed to their upper limits of thermal stability. For this reason, thermal barrier coatings, with a typical composition of ZrO2-7%Y2O3, were developed and applied to the metallic substrate for added protection. Further increases to engine operating temperatures necessitate the development and advancement of thermal barrier coatings. In the past, tremendous effort has been devoted to developing new thermal barrier coating materials and design methods, such as layering, to decrease the rate of heat transport from the gas phase to the substrate coating materials. It is the purpose of this paper to present some of the latest advancements in thermal barrier coatings and to present our approach for designing and modeling their structures.