We use regression discontinuity design to examine the impact of placing into developmental math on science, technology, engineering, and mathematics (STEM) participation in community colleges and whether these relationships differ for underrepresented racially minoritized (URM), women, STEM-oriented, and STEM-aspiring students. Results show that lower math placement was a deterrent to both math progression and STEM participation, especially for those at the margin of placement in transfer-level math. Subgroup analyses suggest that lower math placement may have supported women, and to a lesser extent URM students, in completing transferable STEM credits. For STEM-oriented students, we find suggestive evidence that lower placement deterred them from accumulating transferable credits. We discuss how community colleges can support these students and bolster the community college STEM pathway.