This article focuses on lessons learned from district implementation of Utah Senate Bill 64 passed in 2012, which requires large-scale reform in evaluating teacher quality. This statemandated reformation effort requires all principals to evaluate teacher performance using new state teacher standards adopted in 2011. District implementation efforts used effective professional development that included peer collaboration and practicum experiences as evidenced by successfully certifying all principals in the evaluation of teacher performance. Twenty-seven principals representing nine districts were selected for this qualitative study. Data was collected during a one-on-one interview with each principal to gather insights about district efforts to prepare them individually to effectively evaluate teacher performance. In addition, data were coded and analyzed for evidence of change knowledge principles. The central lesson learned is that sustainable and continuing teacher quality improvements require a continual collective capacity vision and approach at all levels of the educational system. Certifying principals in the use of an improved teacher evaluation tool through effective professional development efforts is one step in achieving improvements in teacher quality. Consideration of the following four components of change knowledge principles foster and strengthen district efforts when implementing strategic targets for the continuation of teacher quality improvements: (a) expand teacher quality improvements to include both individual and collective capacity building opportunities; (b) create a plan of action that builds on efforts to comply with state law and expands implementation efforts to use the evaluation tool for improved student learning through continual teacher quality improvements; (c) provide professional development that includes strategic opportunities for principals to build their capacity in their critical role and responsibilities to continue teacher quality growth; (d) provide supports in the context of a principal's school through practicum experiences that foster the acquisition and sustainability of skills that support teacher quality improvements.