Novice teachers' professional contexts may have important implications for their effectiveness, development, and retention. However, due to data limitations, descriptions of these contexts are often unidimensional or vague. Using 10 years of administrative data from the Los Angeles Unified School District, we describe patterns of new teacher sorting using 24 context measures organized along three dimensions--intensity of instructional responsibilities, homophily, and colleagues' qualifications--and use school-level survey data to measure a fourth dimension--professional culture. Relative to more experienced teachers, novice teachers have placements that are more challenging along the first three dimensions, and composite measures of the dimensions are differentially predictive of teachers' outcomes. This suggests that policymakers should carefully consider placements to better support novice teachers.