Extreme Child Care Access Deserts (ECCADs) are Zip Code Tabulated Areas (ZCTAs) that have too few licensed early learning providers for the estimated population of children. ECCADs shows a lack of providers by eligibility category, alongside the estimated rate of children receiving Early Care and Education (ECE) services, as compared to the total population of eligible children (referred to as Uptake Estimates) by ZCTA. The Persistence map helps show which ZCTAs are frequently categorized as an ECCAD by month. DCYF’s Office of Innovation, Alignment, and Accountability (OIAA) makes use of the definition and methodology for Extreme Child Care Access Deserts developed in Massachusetts. For reference on the methodology, see Hardy et al. 2018 Research Report: Subsidized Child Care in Massachusetts: Exploring geography, access, and equity. This data set comes from the Child Care and Early Learning: Extreme Child Care Access Deserts & Uptake Estimates dashboard (https://dcyf.wa.gov/practice/oiaa/reports/early-learning-dashboards/eccad)