Background/Context: Although professional development using coaching has been widely adopted as a way of improving early care and education practice, only recently have researchers begun to look at the content and features of coaching that lead to desired outcomes. This study examines one of the first projects to explore coaching components among urban community-based childcare programs participating in a city-wide universal prekindergarten program. The project aimed to use coaching to help teachers use a specific set of high-quality practices, known as the Magic 8, shown in other research to improve child outcomes. Purpose/Objective/Research Question: A primary goal of the evaluation was to obtain preliminary evidence of the potential of an early-stage, field-initiated intervention, Interaction-Focused Coaching (IFC), to determine the extent to which additional research or scale-up efforts might be warranted. Outcome questions. To what extent: (1) did teachers increase their use of the Magic 8 and similar classroom practices over time? (2) did teachers increase their knowledge and efficacy regarding effective teaching practices? and (3) were there credible associations between implementation and outcomes? Program implementation was also examined, as were teacher-reported feasibility, value, and perceived gains for themselves and children in their classrooms. Setting: The research took place in a large urban context with community-based childcare centers participating in the city's universal prekindergarten (PreK) program. Children served are predominantly Black (61%), with 14% white, 5% Asian, and 20% other/multiracial. Population/Participants/Subjects: Forty-three teachers in 36 PreK sites completed IFC over three planned cohorts. Of these, 36 teachers were center-based and seven teachers were family child care providers (FCC). Table 1 presents teacher education and demographic characteristics. Intervention/Program/Practice: IFC is an in-class interaction-focused coaching model to engage teachers in using a specific set of high-quality practices called the Magic 8. (See Table 2.) The model comprises a 12-week program with three components: (1) weekly visits of 60-90 minutes by an assigned coach to each teacher's classroom or FCC; (2) follow-up emails after each visit sent from the coach to the teacher, copying the director, summarizing the coach's observations and recommendations with attached/linked resources; and (3) four 3-hour Community of Practice (COP) group meetings of teachers and their coach which focused on sets of Magic 8 practices with videos, resources, and group discussions. Research Design: The approach employed an iterative development design to provide a preliminary level of evidence of the effectiveness of IFC. As such, the sample was modest in size and implementation occurred, as in most development studies, without a comparison group. Data Collection and Analysis: Pre-post analyses examined improvements in observed and reported teacher practices. Data sources: (1) Teacher and director surveys: At baseline, teachers reported education and demographics, and directors reported classroom/program characteristics. At baseline and follow-up, teachers completed: (a) "Teachers' Sense of Self-Efficacy Scale -- Short Form": 12 items about how much the teacher feels she can do for about the kind of phenomena that create difficulties for teachers in their classroom (b) "Knowledge of Effective Teacher-Child Interactions Assessment": 14 multiple-choice response items to short vignettes; correct answers reflect CLASS definitions and high-quality teacher-child interactions. (c) "Knowledge and Implementation of the Magic 8": Using a study-developed tool, teachers reported their views of their own knowledge and frequency of implementation of each practice. (2) Classroom observations by independent trained observers (second and third cohorts): "Teaching Pyramid Observation Tool" (TPOT) is designed to measure fidelity of implementation of environmental, interactional, and instructional practices associated with the Pyramid Model for promoting young children's social-emotional competence. Correlations are low-to-moderate between TPOT-Pilot scores and the domains/dimensions on the CLASS and some observed behaviors show conceptual alignment with teacher use of Magic 8 practices. (3) Coaches' visit logs: Using a project-developed app, coaches reported type and amount of coaching strategies used (e.g., observation, modeling, information sharing, reflection), date/length of visits, and primary and additional Magic 8 teaching practices observed. (4) Coach surveys. "Stage of Change Scale 2.0 -- Mentor/Coach Form": 7-question surveys about each teacher mid-way and at the end about teachers' current level of engagement in and readiness to change their practices. (5) Teacher focus groups gathered feedback on IFC. Findings/Results: The average number of coach-observed Magic 8 practices observed during groups of visits increased steadily and significantly over the weeks of IFC (Figure 1; F(3) = 10.305, p < 0.001). Repeated measures analyses showed that the average number of practices observed during the first visit group was statistically significantly lower than all later visit groups (m = 3.59, p < 0.05) and increased over time; the average number of practices observed in the last visit group was statistically-significantly greater than the first two visit groups (m = 4.51, p < 0.05). The independently-observed TPOT Key Practices Total Score increased significantly from the beginning (m = 47.64) to the end (m = 52.89) of IFC (Figure 2; t(22) =-2.170, p = 0.041). Teacher-reported sense of efficacy and knowledge of effective teacher-child interactions increased statistically significantly for two of three measures. Increases (observed and reported) were not related to teacher education/experience nor self-efficacy. Teachers who were rated by their coach halfway through IFC as more ready to change their practices (t = 0.357, p < 0.01) used more practices in the final visits (F (2) = 10.92, p < 0.001). Teachers who received more coaching visits reported significantly greater knowledge of the Magic 8 at the end of IFC (r = 0.351, p = 0.026). Conclusions. Results show promising evidence of IFC's effectiveness in improving teachers' use of practices that are known to be consistently related to children's developmental gains. IFC was able to successfully improve teachers' use of interaction-focused practices and was deemed valuable and feasible by teachers in PreK classrooms and FCCs. The model worked equally well with teachers of varying educational backgrounds and years of experience. The 12-week program with strategies employed by the coaches during visits, email feedback, and Communities of Practice provided effective dosage to obtain positive results. Results suggest directions for future rigorous evaluation of this approach, with a comparison group and assessing child outcomes, to examine scale-up in PreK centers/FCCs and/or implementation in non-PreK childcare programs.