Prompted by the emergence of alternative pathways to teacher certification as well as federal, state, and local policy directives aimed at raising student achievement, this study explores the extent to which prospective teachers' reasons to teach have or have not changed since before the enactment of such changes in public schools. In addition, the study contributes to the literature on the recruitment and retention of STEM teachers in difficult-to-staff schools through the analysis of reasons to enter teaching and the implications of those reasons for career changers in an alternative teacher preparation program. Data for this study were gathered over the span of participants' entire first year in the classroom through interviews, questionnaires, and application materials. This study found that participants in Alternative Certification in Science and Mathematics (ACSM) express model influences, experiential influences, programmatic influences, race- and gender-related reasons, and vocational reasons as motivation for teaching. In addition, data revealed that participants' reasons to stay in teaching become much more specific over time.