Many Midwestern Catholic schools have implemented professional learning communities (PLCs) to enhance teacher quality and attain school goals. However, not all schools have aligned practices essential to increase maturity in the five PLC dimensions, as defined by Hord. Guided by Hord\u27s framework, this research study investigated teachers\u27 perceptions of PLC maturity in select Catholic schools. A convenience sample allowed an examination of schools engaged in an initiative that included PLCs. Using a sequential explanatory mixed-methods design, the Professional Learning Communities Assessment - Revised was administered to 42 teachers in 4 schools. Quantitative survey data were analyzed using descriptive statistics. Data revealed the dimensions of shared leadership and shared vision and values were most mature in the majority of participating schools. The dimension of shared personal practice was least mature in all participating schools. Demographic data, analyzed using independent sample t tests and a series of ANOVAs, showed some demographic factors had significant findings in individual schools but no single factor had a significant finding in all schools. Results of quantitative data analysis provided direction for qualitative interviews. Four teachers participated in interviews that examined PLC practices affecting maturity. Transcribed interviews were coded and 7 themes emerged: supportive administration, teachers as leaders, shared vision, peer teaching, teacher buy in, too many meetings, and improper use of PLCs. PLC training for administrators and teachers could result in positive social change as school staffs learn to align specific instructional practices with an infrastructure that supports increasing PLC maturity. This increased PLC maturity directly determines a school\u27s ability to improve