ABSTRACT Maintaining the teacher workforce in science, technology, engineering, and mathematics (STEM) has been a perpetual challenge in US public schools' teaching rosters. Prior reports show the supply of new STEM teachers into the profession has declined over time while demand for instruction in STEM fields continues to grow. This paper seeks to document whether and how the STEM teacher workforce in settings that serve higher proportions of students from low‐income families has been impacted by these pressures. It analyzes successive waves of nationally representative teacher survey data in the United States to explore how demographics and qualifications among the secondary STEM teacher workforce in these high‐need settings have fared over time, in comparison against STEM teachers in low‐need settings and non‐STEM teachers in high‐need settings. Results show the STEM teacher workforce in high‐need schools is consistently less likely to be experienced, less likely to hold any degree in a STEM field, less likely to hold a master's degree, and less likely to be fully certified than STEM teachers in more advantaged settings. Yet, surprisingly, the observed gaps in STEM teachers' qualifications (comparing high‐ versus low‐need settings) are either stable or slightly narrowing over time on most measures. Certain STEM fields—namely, physical sciences and computer science—rely on a less qualified workforce than those in math or biology, with low levels of teacher qualifications observed across all settings. Though even when considering field‐specific alignment between teachers' background qualifications and their teaching assignments, the qualifications gap between more and less economically disadvantaged settings has been slowly shrinking in three of four STEM fields analyzed here. In addition to high‐need schools, small schools (based on enrollment size) and charter schools rely more heavily on underqualified STEM teachers.