The purpose of the DaSy Data System Framework (referred to as DaSy framework) is to assist Part C (Early Intervention) and Part B (School-Aged) 619 programs in developing and enhancing high-quality state data systems for the collection, analysis, reporting, and use of their Individuals with Disabilities Education Act (IDEA) data. The DaSy framework is intended to enhance the capacity of Part C and Part B 619 state staff to: (1) "understand" the characteristics and capabilities of a good state data system; (2) "lead or actively participate in" state data system development and enhancement efforts, including cross-agency work; (3) "use" their state data system to comply with IDEA federal reporting requirements and answer important policy and program questions; and (4) "enable" states to continuously improve their system of services and programs to ensure equitable access, services and supports, and positive outcomes for "all" young children with developmental delays and disabilities and their families served under Part C and Part B 619, especially those who have been historically underserved. The Framework contains an Introduction section and is organized around five interrelated subcomponents: (1) Purpose and Vision; (2) Data Governance and Management; (3) System Design and Development; (4) Data Analysis and Use; and (5) Sustainability. Each subcomponent contains one or more quality indicators and multiple elements of quality. [For the original framework (2014), see ED618099.]