In 2018, the National Science Foundation supported the sixth in a series of surveys through a grant to Horizon Research, Inc. (HRI). This series of studies has been known as the National Survey of Science and Mathematics Education (NSSME). Although not designed primarily as an equity study, the 2018 NSSME+ provides data on some indicators of the extent to which students across the nation have equitable educational opportunities. To this end, data from the study were analyzed by four factors historically associated with differences in educational opportunities: (1) percentage of students in the school eligible for free/reduced-price lunch (FRL); (2) community type; (3) percentage of students in the class from race/ethnicity groups historically underrepresented in STEM (HUS); and (4) prior achievement level of the class. This report is organized by these equity factors, with each chapter highlighting the distribution of four educational resources among K-12 schools and classrooms in the United States: (1) nature of instruction; (2) material resources; (3) well-prepared teachers; and (4) supportive context for learning. Data from the 2018 NSSME+, both individual items and composite variables, are shown in tables, with the standard errors for the estimates included in parentheses. Within each equity factor, comparisons were made between groups. In addition, when possible, data from the 2018 and 2012 studies were compared to examine whether the magnitude of differences between groups changed across the two time points. [For "Report of the 2018 NSSME+," see ED598121. For "Are All Students Getting Equal Access to High-Quality Science Education? Data from the 2018 NSSME+," see ED614661.]