Despite policy efforts to increase Advanced Placement (AP) course-taking among Black students, gaps in AP course-taking persist. Many question whether offering more AP courses is a sufficient policy solution. However, few studies have examined the effect of course offerings on disparities within racially diverse high schools. Using national school-level data from the Office for Civil Rights and an instrumental variable approach, we estimated the effect of AP course offerings on within-school Black-White gaps in AP course-taking. We found an additional AP course increased the Black-White AP gap in schools by 1.1 percentage points, net of other variables.