Because of disunity among prominent professional learning community (PLC) authors, experts, and researchers, the literature was studied to develop a ten-element model that represents a unified and reconceptualized list of characteristics of a PLC. From this model, the Learning Community Culture Indicator (LCCI) was developed to measure professional learning community (PLC) implementation levels based on the ten-element model. Exploratory and confirmatory factor analyses were performed to determine the structural validity of the LCCI. Factor analyses provided successful levels of fit for the models tested in representing the constructs of the LCCI. Reliability measures also indicated high levels of internal consistency among the responses to the survey items. Although some items and elements had moderate levels of fit and need additional revisions and validity testing, the LCCI produced substantial evidence that this survey was a valid and reliable instrument in measuring levels of PLC implementation across the ten elements. Because this research validated the LCCI, school leaders can implement, monitor, and diagnose elements of PLCs in their schools. The LCCI also provides a method in which future research can be conducted to empirically support the influence of PLCs and student achievement. Potential uses and recommendations for further research and consideration are presented. A call for more empirical research is made in connecting the PLC reform model to improved student learning. The theory of PLC is at a point of substantiation and growth. The LCCI is recommended as potential tool for studying and facilitating the implementation of PLCs in schools.