Research demonstrating principals' impact on student learning outcomes has fueled the shift from principals as facilities managers to an emphasis on instructional leadership (Hallinger & Heck, 1996; Leithwood, Louis, Anderson, & Wahlstrom, 2004; Marzano, Waters, & McNulty, 2005). Principals are under increasing pressure to carry out effective instructional leadership practices, including those needed to adopt college- and career-ready standards and more comprehensive teacher evaluation approaches. To improve instructional leadership performance, districts are stepping up principal support and oversight by increasing the focus of principal supervisors on principal evaluation and school leadership support functions (Canole & Richardson, 2014; Corcoran, Casserly, Price-Baugh, Walston, Hall, & Simon, 2013; Honig, 2012, 2013; Honig, Copland, Rainey, Lorton, & Newton, 2010). Teacher Incentive Fund (TIF) sites, like many schools and districts nationwide, are implementing new principal evaluation systems intended to be meaningful for both accountability and leadership improvement purposes. We explore in this brief how four TIF grantees are: 1. Training principal evaluators and monitoring principal evaluations to promote rating accuracy and improved performance feedback; 2. Using principal evaluation processes and measures to support principal professional learning and performance; and 3. Providing other supports for principals to improve their leadership. The grantees featured include Broward County School District, Miami-Dade County School District, two districts participating in the Ohio TIF project, and Denver Public Schools. We begin with a brief review of literature about supporting principal evaluators and using evaluation to support principal development. We then provide a summary of each site's evaluation process and describe how the four sites support principal evaluators and principal performance improvement. The brief concludes with questions current and future TIF grantees should consider as they reflect on how their systems are working or plan changes to better support principal supervisors and principals in order to improve supervision and instructional leadership. Principal Evaluation System Summaries are appended.