We use comprehensive data on student teaching placements from 14 teacher education programs (TEPs) in Washington State to explore the sorting of teacher candidates to the teachers who supervise their student teaching ("cooperating teachers" or CTs) and the schools in which student teaching occurs. All else equal, teachers with more experience and higher degree levels are more likely to host student teachers, as are schools with lower levels of historical teacher turnover but with more open positions the following year. Teacher candidates are also more likely to work with CTs of the same gender and race, and are more likely to be placed with CTs and in schools with administrators who graduated from the candidate's TEP. We then assess the impact of these placements on student achievement in the classrooms in which student teaching occurs, and find that a teacher's students perform only slightly worse in math and not significantly better or worse in English Language Arts, all else equal, in years in which the teacher hosts a student teacher than in other years. The negative effect in math is driven by CTs in the lowest quartile of value added, suggesting that more effective CTs can mitigate the impact of hosting a student teacher on student performance.