This report explores teacher retention rates, teacher attitudes, and the characteristics and background of those who remain in teaching. The research is based on a survey of undergraduates ten years after graduation. Comparisons are made between those who remain in teaching, those who once taught but no longer do so, and those who do not teach. This report does not show data for physics specifically, but does show that STEM majors are more likely to leave teaching and not teach in the first place than their non-STEM counterparts.