We examined the effects of teacher education on preservice secondary science and mathematics teacher readiness. The construct of teacher readiness consisted of three dimensions: (1) preservice teachers' understanding of how to implement current standards; (2) their understanding of how to teach multilingual learners (MLs); and (3) their beliefs about their abilities and skills as educators. To determine teacher readiness, a subset of preservice teachers enrolled in six teacher education programs (TEPs) completed a pre- and post-survey. We found that the undergraduate STEM teacher recruitment program was associated with developing preservice teachers' understanding of standards-based instruction but was not associated with the other two dimensions of teacher readiness. We also found that the post-baccalaureate TEPs were effective in developing preservice teachers' understanding of ML instruction, whereas the experimental baccalaureate program was not. Further, we found that teacher readiness did not predict participants' performance assessment (edTPA) scores. Findings suggest that teacher educators and curriculum developers involved in undergraduate STEM teacher recruitment programs should better address language, literacy, and ML instruction. Both teacher recruitment and TEPs should consider ways to strengthen teacher efficacy. Finally, teacher educators should carefully consider how their coursework and field experiences help preservice teachers prepare for the edTPA.