The purpose of the current mixed-methods study was to investigate a model of professional development and classroom-based early reading intervention implemented by the 1st-grade teaching team in a large urban/suburban school district in the southeastern United States. The intervention provided teachers with ongoing embedded professional development through coaching based on an instructional framework of diagnostic strategies designed to promote struggling students' accelerated reading progress. Ten teachers participated along with 45 students (29 intervention students and 16 comparison students). Student-level data sources included Letter-Word Identification, Word Attack, Spelling of Sounds, and Passage Comprehension measures. Teacher-level data sources included semistructured interviews with each teacher at the beginning, middle, and end of the intervention; documents for review; and pre/post questionnaires to gather information about teachers' self-efficacy and demographics. The main conclusions are as follows: (a) struggling 1st-grade students who were eligible for intervention, on average, made sizable gains in all 4 reading outcomes and made significantly greater growth across the year compared to the comparison students in 3 of the reading outcomes; (b) findings from the teacher-level analysis demonstrated that the 1st-grade teaching team had changed perceptions of literacy teaching and learning across the intervention period; and (c) teachers in the 1st-grade teaching team had varied stances with respect to the effectiveness of the intervention activities and professional development.