The Partnership for Pre-K Improvement (PPI) was launched in 2016 as a project with a vision to develop and sustain high-quality, equitable Pre-K programs that produce improved and more-equitable kindergarten readiness and greater academic success for children through the early elementary grades. The multiyear, multistate (Oregon, Tennessee, and Washington) effort aimed to learn in partnership with states across government leaders, advocates and researchers about how to systematically improve the quality of Pre-K at scale. This report highlights the work achieved by the state leaders, researchers and advocates in Oregon, Tennessee and Washington as part of their PPI strategic vision for improvement. It also describes five foundational assumptions implicit in the PPI strategy that together shaped the design, approach and implementation of the work.