The System Transformation for Equitable Preschools (STEP Forward with Data) Framework was developed to help preschool systems leaders understand where in the preschool system there may be inequities in how children and families are accessing, being supported by, and experiencing the system. The Framework offers preschool systems leaders a pathway to answer common questions about preschool using data in a consistent, equity-centered way. The Framework document first establishes the rationale for developing a unifying data framework in preschool. Second, it details the goals of the Framework, including guidance for preparing to use it. The Framework then provides a list of essential questions which preschool systems leaders may want to answer about their preschool system, organized around six steps in the preschool system. For each step, the researchers describe how children, families, and workforce members experience the system and establish the relevant questions that could be answered at each step. These essential questions are broken down into recommended metrics that can help answer the question using data, which also include suggested ways to calculate the metric, the level at which to collect the data, and example data sources. Finally, a glossary that defines terms used throughout the Framework.