Previous literature reported that Black students receive out-of-school suspensions (OSSs) and expulsions at disproportionately higher rates and have lower test scores than White students. This study provides recent evidence on the relation between racial disparities in discipline and in achievement, with particular focus on achievement gains, in schools across the nation. We link school-level discipline data in 2017-2018 from the Civil Rights Data Collection (CRDC) to student-level assessment data from NWEA. Leveraging assessment data in the fall, winter, and spring for 1,308,004 students in grades 6-8 in 6,841 schools, this is the first study to estimate the association between exclusionary discipline and within-year academic gains. We report two main findings. First, Black-White suspension gaps and achievement gaps persist (correlation= 0.15 for math, 0.19 for reading) in the vast majority of schools in 2017-2018 despite the announcement of many reforms in school discipline practices. Second, Black-White disparities in exclusionary discipline rates are associated with lower learning rates during the school year for Black students in math but there is no association for reading. These findings point to discipline disparity as a key factor contributing to the expansion of Black-White achievement gaps during the school year reported in the extant literature.