Limited attention has been placed on the relationship between developmental math and STEM outcomes in community college. We therefore examine one particular experience during the transition from high school to college called math misalignment, which occurs when college students are placed lower in math than is warranted given their high-school course-taking history and record of achievement. Drawing on analysis of linked high school and community college student records, we find that a majority of students in the study sample experienced math misalignment in community college. Moreover, math misalignment especially hindered STEM-aspiring students from pursuing STEM pathways. STEM-aspiring students who experienced math misalignment were less likely to complete STEM courses than STEM-aspiring students who were directly placed in transfer-level math. This study underscores the importance of aligning academic standards across high-school and postsecondary institutions as a means of improving STEM participation.