In practice, teacher induction is common, but induction that is intensive, comprehensive, structured, and sequentially delivered in response to teachers' emerging pedagogical needs is less so. Congressional interest in formal, comprehensive teacher induction has grown in recent years. The National Center for Education Evaluation and Regional Assistance within the U.S. Department of Education's (ED) Institute of Education Sciences (IES) contracted with Mathematica Policy Research, Inc. (MPR), to evaluate the impact of structured and intensive teacher induction programs. The study examines whether comprehensive teacher induction programs lead to higher teacher retention rates and other positive teacher and student outcomes as compared to prevailing, generally less comprehensive approaches to supporting new teachers. More specifically, the study is designed to address five research questions on the impacts of teacher induction services: (1) What is the effect of comprehensive teacher induction on the types and intensity of induction services teachers receive compared to the services they receive from the districts' current induction programs?; (2) What are the impacts on teachers' classroom practices?; (3) What are the impacts on student achievement?; (4) What are the impacts on teacher retention?; and (5) What is the impact on the composition of the district's teaching workforce? Statistically significant differences between the treatment and control groups were identified in the amount, types, and content of induction support teachers reported having received, both in the fall and the spring of the intervention year. Although treatment teachers reported receiving more mentoring than did control teachers; were more likely than control teachers to report participating in specific induction activities; and spent more time in certain professional activities than did control teachers during the three months prior to the spring survey, summarized comparisons between treatment and control groups found: (1) No impacts on teacher practices; (2) No positive impacts on student test scores; (3) No impacts on teacher retention; and (4) No positive impacts on composition of district teaching workforce. This report focused on the first year of findings only. The research team is conducting longer term follow-up to include additional collection of test score and teacher mobility data. Eight appendices are included: (1) National Data on Teacher Induction; (2) Analysis Weights; (3) Impact Estimation Methods; (4) Classroom Observation Methods; (5) Reference Tables for Chapter II; (6) Supplemental Tables for Chapter IV; (7) Supplemental Tables for Chapter V; and (8) Supplemental Figures. (Contains 43 footnotes, 15 figures and 101 tables.)