Over the past three years, the Boston Birth to Eight Collaborative has convened more than 200 individuals and organizations from across the early childhood field--center and family-based providers, pediatricians, public health researchers, hospitals, family engagement organizations, and parents--to ensure all children are ready for sustained success. The inaugural "State of Early Education and Care" report brings together for the first time data from the Boston Public Schools, Boston Public Health Commission, Massachusetts Department of Early Education and Care (EEC), U.S. Census Bureau, City of Boston Census and the United Way DRIVE Initiative. This report focuses on supply, demand and gaps in child-care seats (availability, quality and affordability). It also explores disparities based on child and family characteristics, including child/family demographics, and maternal/adult and child health. This first "State of Early Education and Care in Boston" aims to provide policy makers, philanthropists, and early education and care practitioners with information about gaps and opportunities around supply and demand of early education and care in the city. It will guide the Boston Opportunity Agenda and Birth to Eight Collaborative's citywide plan and will help to identify where additional child-care slots are needed, areas for quality improvement, and what other family supports are necessary. [This report was produced by the Birth to Eight Collaborative.]