Designers of professional development training often presume that teachers are able to apply new concepts classroom practice, but fail to include teacher voice, provide systemic follow-up, collegial support, and evaluation (Guskey, 2002; Joyce & Calhoun, 2010; McAdams, 2007). The study investigated differences between new, non-tenured and experienced, tenured teacher perceptions of the impact of one or more graduate courses offered through a school district designed professional development program. Participation was voluntary for experienced teachers and mandatory for new teachers. The study also explored teacher perceptions of impact on classroom practice based on Guskey's (2000) Five Critical Levels of Professional Development Evaluation. This case study utilized mixed methods and included a researcher-generated survey and three focus groups. The sample was comprised of prek-12 teachers from a Midwest, urban school district. Teachers revealed their perceptions of impact on classroom practice by identifying one or more researcher-generated Impact Statements linked to each course. The study concluded that teachers perceived only one graduate course had a significant impact on classroom practice. Tenured teachers reported course topics and activities related to their learning needs but did not impact classroom practice. Non-tenured teachers concluded that the graduate course topics were similar to the undergraduate level, should not be mandatory, and did not meet the professional needs of new teachers. Teachers also evaluated course impact in relationship to Levels 1 and 2 of Guskey's (2000) Five Critical Levels of Professional Development Evaluation, but not sufficient to impact change in classroom practice and student learning. The implications of the study suggest the need for prek-12 organizations to address learning needs according to tenure and engage teachers and adminstrators as collaborative partners in the design, implementation, and evaluation of professional development. Professional development would have greater value if school district efforts included research-designed models, such as Guskey's (2000) and Joyce and Showers (1987), which purposefully focus on the transfer of knowledge and skills from the workshop to the workplace. Moreover, the credibility of school leaders would improve if they assumed an active role in learning with teachers and providing resources necessary to change teacher practice to impact student outcomes. [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.]