The purpose of this mixed-methods phenomenological study was to investigate the relationship between professional learning community (PLC) implementation and teachers' perceptions of engagement, professional collaboration, professional growth, and ultimately collective teacher efficacy. This research study collected data from elementary school teachers in a suburban school district located in southern California. The research instrument collected quantitative data using Likert scales along with qualitative data (open-ended responses) in a survey format. The school district in which the study was conducted has some universal practices in place that support PLC implementation. The goal was to understand if PLC implementation, as perceived by teachers, has a relationship with teachers' engagement, professional collaboration, and/or professional growth. The results of the Pearson correlational analysis indicate that there is a statistically significant (p < 0.05) positive relationship between PLC implementation and each of the independent variables; thus, the more deeply PLC is implemented, the more teachers reported positive impacts on engagement, professional collaboration, and professional growth. Collective teacher efficacy (CTE) is linked to successful academic outcomes for students and has been identified as an accelerant of learning, so it is important to determine practices that may have an influence over teachers' efficacy beliefs and or collective efficacy beliefs. The results of this study also indicate a statistically significant positive relationship between PLC implementation and CTE. PLC is a specific concept of professional development that can positively impact teachers in many areas. [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.]