We estimate male-female test score gaps in math and English language arts (ELA) for nearly 10,000 U.S. school districts using state accountability data from third- through eighth-grade students in the 2008-2009 through 2015-2016 school years. We find that the average U.S. school district has no gender achievement gap in math, but there is a gap of roughly 0.23 standard deviations in ELA that favors girls. Both math and ELA gaps vary among school districts; some districts have more male-favoring gaps and some more female-favoring gaps. Math gaps tend to favor males more in socioeconomically advantaged school districts and in districts with larger gender disparities in adult income, education, and occupations; however, we do not find strong associations in ELA.