This technical brief examines the 2008/09 reading and math proficiency levels among subgroups of Arizona public school students defined by students' race/ethnicity (American Indian, Asian, Black, Hispanic, and White), English language learner status (English language learner students and non-English language learner students), disability status (students with and students without disabilities), and economic status (students receiving and those not receiving free or reduced-price meals). Responding to an Arizona Department of Education request, the brief describes how student subgroup performance differs by school level (elementary, middle, and high) and school type (Title I Schools in Improvement [schools serving economically disadvantaged students and participating in the federal school improvement program intended to improve academic performance in schools not making adequate yearly progress for at least two consecutive years], Title I Schools Not in Improvement, and non-Title I schools). The same analyses were conducted for charter schools. Key findings include: (1) Across all school levels and school types, reading proficiency ranged from 26 percent for English language learner students to 84 percent for Asian students, White students, and students not receiving free or reduced-price meals. Overall and in 10 of 11 student sub-groups, elementary, middle, and high school proficiency rates were within 6 percentage points of one another. However, the margin was wider (13 percentage points) for English language learner students, ranging from 16 percent in high schools and 17 percent in middle schools to 29 percent in elementary schools; (2) Across all levels of charter schools, reading proficiency ranged from 31 percent for English language learner students to 89 percent for Asian students. Reading proficiency rates declined overall and in 7 of 11 student subgroups from elementary to middle to high school; (3) Across all school levels and school types, math proficiency ranged from 34 percent for English language learner students to 86 percent for Asian students. Overall and in 10 of 11 student subgroups, elementary, middle, and high school proficiency rates were within 10 percentage points of one another. However, the margin was wider (16 percentage points) for English language learner students, ranging from 22 percent in high schools and 25 percent in middle schools to 38 percent in elementary schools; (4) Across all levels of charter schools, math proficiency ranged from 35 percent for English language learner students to 86 percent for Asian students. Math proficiency rates declined from elementary to middle to high school overall and in all but one student sub-group (English language learner students); (5) In both reading and math, Asian students (84 percent in reading and 86 percent in math) and White students (84 percent in reading and 82 percent in math) scored proficient at higher rates than did the overall student body (72 percent in reading and 71 percent in math). Among the three racial/ethnic subgroups with proficiency rates below the overall rate, American Indian students scored consistently lower (53 percent in reading and 51 percent in math) than Black students (65 percent in reading and 60 percent in math) and Hispanic students (62 percent in reading and 62 percent in math); and (6) In both reading and math, in all but one subgroup, students in non-Title I schools had higher proficiency rates than did students in both Title I Schools Not in Improvement and Title I Schools in Improvement. However, English language learner students in Title I Schools Not in Improvement had proficiency rates (30 percent in reading and 38 percent in math) 4 percentage points higher than English language learner students in non-Title I schools (26 percent in reading and 34 percent in math). Appended are: (1) Summary of Arizona's accountability system (excerpted from Crane et al. 2008); (2) Data and methodology; and (3) Data for alternative, K-12, and other schools. (Contains 13 tables and 3 notes.)