This is the appendices for the full report, "Identifying the Nation's Lowest Performing Schools: Shifts Following the Passage of the Every Student Succeeds Act (ESSA)." This study examines state identification of schools for the most intensive support to see how changes in federal laws and regulations played out nationally and at the state level, by comparing schools identified just before and just after ESSA's implementation. Specifically, it looks at two time points: 2016-17, during which there were two distinct policy contexts, with most states operating under waivers but seven states still operating under the previous No Child Left Behind policies, and 2018-19, when all states were expected to be following ESSA regulations for the first time. Of particular interest is whether the number and characteristics of identified schools--including their average student achievement and demographics--differed when comparing the set of schools identified under ESSA with the set of schools identified just before ESSA. The appendices provide supporting details on the policy being evaluated, the study methods, and supplementary analyses for the findings presented.