This article reports on a study designed to estimate the effect of high school coursetaking in the algebra-calculus pipeline on the likelihood of placing out of postsecondary remedial mathematics. A nonparametric variant of propensity score analysis was used on a nationally representative data set to remove selection bias and test for an effect among all comparable students and among students least likely to enroll in precalculus, trigonometry, or calculus. The effect failed to reach practical significance among all comparable students and was particularly weak among students least likely to take precalculus, trigonometry, or calculus. These findings suggest that the regression-based results that factor strongly into discussions on high school graduation requirements for mathematics coursetaking contain substantial selection bias.