A main goal of the No Child Left Behind Act (NCLB) is to close gaps in test scores between different groups of students while raising achievement for all groups. Of particular concern are the persistent achievement gaps between African American, Latino, and Native American students and their white and Asian counterparts, and between students from low-income families and those who are not low-income. For these gaps to narrow and eventually close, not only must achievement for lower-scoring subgroups increase, but it must go up at a faster rate than for the higher-scoring comparison group. A related question is whether achievement for all subgroups has improved across the scoring scale--at the "advanced" and "basic" levels as well as at the "proficient" level, which receives the most scrutiny under NCLB. In 2009, the third year of a multi-year study of student achievement, the Center on Education Policy (CEP) did three types of analyses of data broken out by subgroups from the state tests used for NCLB accountability. First, it examined grade 4 state test results at three achievement levels--basic-and-above, proficient-and-above, and advanced. The goal was to see whether students from various racial/ethnic groups and low-income students have made gains at all three achievement levels and whether progress is lagging at any level for specific subgroups. Second, it looked at gaps between subgroups in the percentages of students scoring at or above the proficient level at three grade levels (grade 4, grade 8 in most cases, and a high school grade). Third, it analyzed gaps between subgroups in average test scores at three grade levels. CEP did these last two analyses to see whether achievement gaps at the elementary, middle, and high school grades have narrowed, widened, or stayed the same since 2002, when NCLB took effect and required states and school districts to pay greater attention to the achievement of subgroups. This report describes the trends found for African American, Latino, Native American, Asian, and white students, and for low-income and non-low-income students. Achievement trends for students with disabilities, English language learners, and male and female students will be discussed in future reports in this series. (Contains 17 tables, 2 boxes, 3 figures and 5 footnotes.) [For "State Test Score Trends through 2007-08, Part I: "Is the Emphasis on "Proficiency" Shortchanging Higher- and Lower-Achieving Students?," see ED506121. For "State Test Score Trends through 2007-08. Part II: Is There a Plateau Effect in Test Scores?," see ED506122.]