Improving STEM education is pivotal to our country's economic future and security. Unfortunately, most young students have limited access to standards-based science education. Science instruction is notoriously difficult to implement in the early grades. This dissertation explored the root causes for the lack of effective science instruction in elementary schools, including accountability testing, instructional time, historically weak standards, family factors, teacher efficacy, and professional development. This study aimed to understand how elementary school teachers' attitudes promote or hinder the implementation of science instruction. This study's primary driver to improve science education in the early grades was a curriculum-based professional learning community (PLC). The PLC sought to promote collective teacher efficacy in teaching science by engaging participants in scientific inquiry (i.e., 5E Inquiry-Based Instructional Model) using STEM resources, analyzing student data, making instructional decisions, and developing common science assessments. Implementation of the study's intervention relied on adaptive leadership, transformational coaching, constructivism, and other pertinent educational learning theories. The first round of intervention was a virtual PLC with a vertical team of six classroom teachers and a curriculum specialist. Data revealed an increase in participants' self-efficacy levels toward science curricula and the 5E Inquiry-Based Instructional Model, but there was a minimal improvement in classroom implementation. Iterations to the intervention included opportunities for instructional coaching in a hybrid environment. I personalized coaching strategies according to participants' personalities and preferences. Revisions to the intervention aimed to enrich collaboration between teachers and coaches and transform science education at the elementary school level. This study used improvement science as a methodology and mixed methods to examine a curriculum-based PLC's effects on teachers' self-efficacy toward inquiry based science instruction. I collected data through surveys, interviews, observations, and document analysis (e.g., curriculum maps, lesson screeners). The quantitative and qualitative data collection indicated that the study's drivers directly or vicariously empowered teachers and increased their self and collective efficacy levels. Findings from this study suggest that vertical teaming is a viable approach to elementary school teachers' professional development. Results indicate that subject based PLCs built on collaborative lesson planning, reflective curricular guides, and ongoing coaching can improve teacher efficacy in designing and implementing standards based instruction. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]