In the United States, mothers of children younger than school age have significantly lower rates of labor force participation than other prime-age adults (those aged 25 to 54). Observers often attribute this pattern partly to a lack of available and affordable childcare. In a 2023 national survey, parents cite “costs” and “lack of open slots” equally as the largest barriers to accessing childcare. Because they cannot access childcare, many mothers have to reduce working hours, work part time instead of full time, or leave the workforce altogether. This report quantifies how childcare availability and cost impact labor market outcomes for mothers of young children in New England. Using detailed childcare licensing records from 2010 to 2023, the authors construct neighborhood-level measures of childcare supply and cost.