Last year, Hispanic and African American high school graduates met ACT's College Readiness Benchmarks in English, reading, mathematics, and science at substantially lower rates than did Asian and White graduates. For example, the rate of White graduates who were college ready in English (77%) was twice that of their African American peers (35%). Unfortunately, evidence of such academic achievement gaps--as measured by College Readiness Benchmarks and other measures of academic achievement--is all too common and persistent. While much attention has been paid to achievement gaps, growth gaps have been largely overlooked. This brief investigates race/ethnicity-based growth in achievement gaps for ACT-tested 2011 high school graduates. First it looks at growth in achievement gaps among the four largest racial/ethnic groups (i.e., African American, Asian, Hispanic, and White), and then it highlights the gaps of the two largest racial/ ethnic minorities in the United States--African American and Hispanic students. Appended are: Table A1: N-Counts, Percentages and Average ACT Scores, by Race/Ethnicity; Table A2: Average EXPLORE, PLAN, and ACT Scores and Score Gains, by Race/Ethnicity; and Table A3. Gap between African American and Hispanic Students from EXPLORE to PLAN and PLAN to ACT.