The National Assessment of Educational Progress (NAEP), in partnership with the National Assessment Governing Board and the Council of the Great City Schools (CGCS), created the Trial Urban District Assessment (TUDA) in 2002 to support the improvement of student achievement in the nation's large urban districts. NAEP TUDA results in mathematics and reading are based on representative samples of 1,100 to 2,300 public school students at grade 4 and 900 to 2,100 public school students at grade 8 in each participating urban district in 2013. Twenty-one urban districts participated in the 2013 assessments.This one-page report presents overall results, achievement-level percentages and average score results, scores at selected percentiles, average scores for district and large cities, results for student groups in 2013, and score gaps for student groups. In 2013, the average score of eighth-grade students in Baltimore City was 252. This was lower than the average score of 258 for public school students in large cities. The average score for students in Baltimore City in 2013 (252) was higher than their average score in 2011 (246) and in 2009 (245). The score gap between higher performing students in Baltimore City (those at the 75th percentile) and lower performing students (those at the 25th percentile) was 38 points in 2013. This performance gap was not significantly different from that in 2009 (39 points). The percentage of students in Baltimore City who performed at or above the NAEP "Proficient" level was 16 percent in 2013. This percentage was not significantly different from that in 2011 (12 percent) and was greater than that in 2009 (10 percent). The percentage of students in Baltimore City who performed at or above the NAEP "Basic" level was 61 percent in 2013. This percentage was greater than that in 2011 (54 percent) and was not significantly different from that in 2009 (54 percent). [For "The Nation's Report Card: A First Look--2013 Mathematics and Reading Trial Urban District Assessment. NCES 2014-466," see ED544551.]