This study aimed to investigate the influences instructional coaching had on middle school math teachers. Accountability demands have impacted teaching and learning, and the push to use high stakes tests to measure teacher quality and effectiveness has limited teacher autonomy, agency, and efficacy. Teachers need professional learning that supports accountability demands and empowers them to be active participants in their own learning. The problem, however, is that teachers are rarely afforded professional learning that empowers them to be actively engaged in their own learning. Instructional coaching is a learning design that provides ongoing, job-embedded professional learning, which allows for active participation in one's own learning. The researcher offered five middle school math teachers instructional coaching for this study. This bounded case study used participatory action research (PAR) to understand how instructional coaching influenced participants' professional learning and instructional practices. Due to the small number of participants, multiple data sources were collected using interviews, teacher and meeting observations, peer observations, and monthly reflections. The study revealed that instructional coaching positively influenced the participants' practices and learning. Key findings implied schools implementing instructional coaching should (a) build trusting relationships, (b) use standards to guide professional learning, (c) include structures to support and sustain professional learning, (d) allow for collaboration and collective responsibility, and (e) use data to reflect and inform practices. Effective instructional coaching can have a positive influence on teachers and improve instructional practices leading to enhanced student outcomes. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]