Previous research indicates that the principal is second to the teacher in their impact on student learning. However, oftentimes principals enter their position lacking the skills and knowledge of an effective instructional leader. Moreover, districts may lack the internal capacity to support principal's professional development and learning. If improvements in teacher practice and student achievement are the desired outcome, then systems of support must be in place to support principals. This evaluation sought to explore the effectiveness of the administrator-coaching model and the theory of action being employed by the McClaren County Office of Education (MCOE, a pseudonym) Systems Improvement Unit (SIU, a pseudonym) employed the Context, Input, Process, and Product (CIPP) Model of program evaluation. The researcher used a triangulation mixed method design to determine the impact of the coaching services provided. Participants in this study were selected purposefully and included coaches, principals, and principal supervisors. Findings suggest the MCOE delivered effective coaching services based on what research deems vital for effective school leadership. The Blended Coaching Model guided the facilitation of coaching services, and principals realized positive changes in leadership practices as a result of coaching. Despite operating without an explicit coaching framework and a universally shared understanding of the theory of action that guided coaching services, coaches are impacting principal leadership in a positive way. It is recommended the SIU revisit the theory of action as a team in order to improve understanding and alignment of its coaching services. [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.]