The purpose of this qualitative methods research is to study the development of teacher leaders in the implementation of grade-level and/or departmentalized professional learning communities across eight parochial schools. When working with teacher leaders in the leading of grade-level or departmentalized professional learning teams, there are many facets involved in the growth and development of teacher leaders. Teacher leaders will be given the guidance and tools to lead their grade-level or departmentalized professional learning team effectively. Teacher leaders will use the knowledge and skills they possess related to leadership and professional learning communities with the help of building administrators to engage their professional learning teams in talking about teaching and learning within their own classrooms. They will develop structured meetings, present current research, and guide collaborative discussions that bring their teams together in collaboration of the best practices in education and the problems of practice within their own classrooms. The study will identify the teacher leaders' leadership skills and effectiveness of their roles as teacher leaders in their individual professional learning communities. Research Question 1: How do teacher leaders grow and develop their leadership skills, based on Domains I and III, with the exception of F in Domain III, of the Teacher Leader Model Standards developed by the Teacher Leadership Exploratory Consortium (2010), in collaborating with building principals and professional learning community teams among teachers in grade-level or departmentalized teams through participation in a teacher leader program? Research Question 2: How do teacher leaders utilize their leadership skills to effectively collaborate with their professional learning communities, based on Domains I and III, with the exception of F in Domain III, of the Teacher Leader Model Standards developed by the Teacher Leadership Exploratory Consortium (2010), in collaborating with building principals and professional learning community teams among teachers in grade-level or departmentalized teams through participation in a teacher leader program? The qualitative results will be identified by examining and comparing the teacher leader surveys-pre-teacher leader program, administrator observation and feedback forms, and teacher leader surveys-post-teacher leader program. The results will show that teacher leaders grow and develop their leadership skills, based on Domains I and III, with the exception of F in Domain III, of the Teacher Leader Model Standards developed by the Teacher Leadership Exploratory Consortium (2010), when collaborating with building principals and professional learning community teams among teachers in grade-level or departmentalized teams through participation in a teacher leader program. In addition, the results will show that teacher leaders utilize their leadership skills to effectively collaborate with their professional learning communities, based on Domains I and III, with the exception of F in Domain III, of the Teacher Leader Model Standards developed by the Teacher Leadership Exploratory Consortium (2010), in collaborating with building principals and professional learning community teams among teachers in grade-level or departmentalized teams through participation in a teacher leader program. [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.]