This report presents the results for Part I of the study focusing on the performance of American Indian and Alaska Native (AI/AN) fourth- and eighth-graders on the 2007 National Assessment of Educational Progress in reading and mathematics. A national sample of approximately 10,100 AI/AN students at grades 4 and 8 participated in the 2007 reading assessment and 10,300 in the mathematics assessment. Results from this study are compared to those from the first NIES conducted in 2005. The results for 11 states with relatively large populations of AI/AN students are presented in addition to the national results. In both reading and mathematics, overall scores for AI/AN fourth and eighth-graders showed no significant change since 2005 and were lower than the scores for non-AI/AN students in 2007. In 2007 at both grades, AI/AN students attending schools in which less than 25 percent of the students were AI/AN scored higher than their peers attending schools with higher concentrations of AI/AN students, and those attending public schools scored higher than their peers in Bureau of Indian Education schools. Although overall average scores for AI/AN students were lower than the scores for non-AI/AN students at both grades in 2007, they were not consistently lower than the scores for all racial/ethnic groups. Average scores in both grades for AI/AN students were lower than the scores for White and Asian/Pacific Islander students. Scores for higher-performing AI/AN students were higher than those of their Black peers in both grades. In reading, AI/AN fourth-graders attending city schools scored higher than their Hispanic peers, and AI/AN eighth-graders attending rural schools scored lower than their Hispanic peers. In mathematics, average scores for AI/AN students in both grades were not significantly different from their Hispanic peers. (Contains 39 figures and 30 tables.) [For Part I of the 2005 edition of this study, see ED491693. For Part II of the 2005 edition of this study, see ED493678.]