Teacher evaluation is a pressing issue for school personnel and district administrators across the country, as an increasing number of states mandate that their districts develop and implement new evaluation systems. In 2010, Illinois enacted the Performance Evaluation Reform Act (PERA), requiring every district in the state to adopt new teacher evaluation systems by 2016-17 that address both teacher performance and student growth. Designing and Implementing the Next Generation of Teacher Evaluation Systems examines the experiences of five case study districts in north, central, and southern Illinois - representing a variety of evaluation approaches, each at different stages of planning and implementation - as they designed and implemented new teacher evaluation systems to fulfill the requirements of PERA. Based on qualitative interviews with members of each district’s evaluation committee, the brief provides a snapshot of how districts assessed and dealt with challenges around cultivating buy-in and understanding; using evaluations for instructional improvement; and reducing the burden on principals. In addition, it examines the on-going challenge of incorporating measures of student growth into teacher evaluation systems. The challenges faced by these early adopter districts and the strategies they used to overcome them are relevant to other districts as they engage in their own design and implementation processes.