The "What Were the Reach and Impact of the Oregon Promise Financial Aid Program in Its First Two Years?" study examined Oregon Promise, a program that promotes students' postsecondary attainment by covering nearly all community college tuition. The study used student data from K-12 public schools, Oregon Promise applications, and postsecondary records to examine which public high school seniors the program reached and served and to assess the program's impact on high school graduates' postsecondary outcomes in its first two years. The study found that Oregon Promise applicants generally reflected the demographic composition of all Oregon public high school seniors in 2015/16 and 2016/17, although applicants were more likely to be female and less likely to have received special education services. Oregon stakeholders can use the findings to better understand the reach and impact of the Oregon Promise program. This document presents the following three appendixes that accompany the study: (1) Oregon Promise; (2) Methods; and (3) Supporting analysis. [For the full report, see ED615645. For the Study Snapshot, see ED615646.]