These are the appendixes for the report, "English Proficiency and the Pandemic: How Texas English Learner Students Fared during the COVID-19 Pandemic. REL 2023-144." This study examined levels of English proficiency before and during the COVID-19 pandemic among English learner students in grades 3-12 in Texas. In 2020-2021, nearly 750,000 students in grades 3-12--approximately one in five Texas students--were English learner students. In accordance with Texas state law and the Every Student Succeeds Act, English proficiency is measured annually using a statewide assessment, the Texas English Language Proficiency Assessment System (TELPAS), which assesses English learner students' listening, speaking, reading, and writing skills in English. This study focused on TELPAS scores among students who took the test in 2020-2021 and compared those scores with a matched cohort of similar students from 2018-2019. Three appendixes are included in this document: (1) Methodology; (2) Supporting tables; and (3) Supplemental analyses. [For the full report, see ED623461.]