The purpose of this study was to compare the algebraic performance gains of high school students who enroll in an integrated mathematics course pathway (i.e., Integrated Mathematics I-II-III) to the algebraic performance gains of high school students who enroll in a subject-specific course pathway (i.e., Algebra I-Geometry-Algebra II). Several studies have been performed in which researchers examined relationships between mathematics outcomes and the course-taking patterns of high school students enrolled in subject-specific course pathways. However, there is little extant research in which researchers have investigated effects of content organization on students' learning and achievement. Therefore, this study addresses calls for more studies that examine the high school mathematics performance of students who learn from subject-specific and integrated course pathways. Data from a large scale observational study known as the High School Longitudinal Study of 2009 was used to compare relationships between the course pathways and students' performance on an assessment of algebraic skills. A pretest-posttest study design was used to statistically compare gain scores of high school students who learn from subject-specific course pathways to the gain scores of a comparable group of high school students who learn from integrated course pathways. Propensity score matching was used to reduce the threat of selection bias due to nonrandom assignment. The results revealed no statistical differences exist in the algebraic performance gains between high school students who learn mathematics from integrated course pathways and high school students who learn from subject-specific course pathways. Suggestions for future research are discussed.