This study is motivated by an ongoing debate about the kinds of schools that make for the best field placements during pre-service preparation. On the one hand, easier-to-staff schools may support teacher learning because they are typically better-functioning institutions that offer desirable teaching conditions. On the other hand, such field placements may leave new teachers unprepared to work in difficult-to-staff schools and with underserved student populations that need high quality teachers the most. Using administrative and survey data on almost 3,000 New York City teachers, their students, and their schools, this study finds that learning to teach in easier-to-staff field placement schools has positive effects on teacher retention and student achievement gains, even for teachers who end up working in the hardest-to-staff schools. The proportion of poor, minority, and low-achieving students in field placements is unrelated to later teacher effectiveness and retention suggesting something beyond student populations explain these results. (Contains 12 tables and 19 notes.)