This report is a compendium to the framework that emphasizes three important messages: 1) there is an evidence base for the policy areas and policy foundations identified in the Birth through Eight State Policy Framework; 2) the years starting at birth and continuing through age eight are a critical time for achieving good health, strong families, and better learning outcomes in early childhood and later in life; and 3) the supports and experiences that children receive have a cumulative effect—each experience influences the next and sustains previous growth and development.