Although results showing coaching effectiveness are accumulating, coaching is often included with other forms of Professional Development (PD) support including teacher in-service (Powell, Diamond, Burchinal, & Koehler, 2010; Kretlow et al., 2011), access to an annotated video library (Allen et al., 2011), and access to ongoing learning communities (Gallucci, Van Lare, Yoon, & Boatright, 2010; Matsumura, Garnier, & Spybrook, 2012). The presence of multiple intervention components obscures the unique effect of coaching and makes drawing conclusions about coaching effectiveness impossible. There is a critical need for identifying effective, sustainable approaches for teacher PD in delivering instruction to foster science practice skills. The purpose of this research study was to: (1) determine the effects of a professional development intervention comprised of a summer institute and follow-up technology-delivered instructional coaching on teacher and student science practice knowledge, skills, self-efficacy, and engagement; and (2) isolate specific effects of coaching when combined with more traditional teacher workshops. The intervention model described here was designed to equip middle and high school science teachers with knowledge and skills to use a guided scientific inquiry approach to teach science practice skills integrated into content as specified by Next Generation Science Standards (NGSS). The project involved a randomized controlled trial aimed at addressing the following research question: What is the impact of a summer institute focused on guided scientific inquiry with follow-up coaching (treatment) versus no professional development (control) on (a) teacher science practices knowledge, skills, self-efficacy, and beliefs and (b) student science practices knowledge, skills, engagement and self-efficacy? A secondary question involved the independent effects of the summer institute and coaching: What were the separate effects of the summer institute and coaching on teacher and student outcomes? The study was conducted with 124 science teachers (63 treatment and 61 control) from 110 rural schools (61 treatment and 49 control) in Nebraska and Iowa. Results from this study show the promise of coaching and its value added to traditional teacher in-service. While this study shows the promise of coaching in impacting teacher change, more research is needed to investigate what specific aspects of the coaching process (i.e., rapport and trust between teacher and coach, coach qualifications, teacher self-reflection) are most responsible for these effects.