My research focuses on Illinois' public pre-K initiative that began in 2007 and was geared toward low-income and academically at-risk 3- and 4-year-olds. I examine the quantity, price and quality of the overall set of child care options available within a given community after public pre-K enters the market. I also consider the consequences of targeted public pre-K on these same outcomes for child care options available to younger children (infants and toddlers). Illinois' public pre-K program offers an ideal case study for this analysis, as it serves a sizeable share of 3- and 4-year-olds in the state – 20 and 26 percent respectively (Friedman-Krauss et al., 2018) – but does not come close to universal coverage, nor does it enroll more advantaged families who might otherwise have access to early education in the absence of public intervention. The study was designed in partnership with the Illinois Department of Human Services' Office of Early Childhood (responsible for CCDF administration) and the Illinois Network of Child Care Resource and Referral Agencies. Findings from the study will inform the following CCDF research topic priorities; issues related to increasing access to high quality care (topic 2), increasing access to, and quality of, care for infants and toddlers (topic 4), and factors promoting or hindering partnerships among child care providers and other early childhood systems (topic 11). The results of the research will be relevant to policymakers at all levels of government as they consider how and for whom to fund early care and education services in order to lower barriers and address gaps in child care access.