Early childhood education is often offered through a mixed delivery system: including center-based and family child care homes, Head Start, and public school settings. The purpose of this study was to understand the feasibility of implementing Cognitive ToyBox (CTB), a combination observation and game-based formative assessment solution, with Pre-K providers that operate within stand-alone, center-based child care settings that receive public funding. With support from the Louisiana Department of Education, the WestEd team conducted a four-week implementation study of Cognitive ToyBox with four nonpublic school center-based Pre-K providers during Summer 2021. The purpose of the study was to understand the degree to which LA Pre-K providers could leverage CTB assessment as intended, get feedback on CTB’s new family engagement module, and gather additional data that CTB could use for reliability and validity analysis. Overall, teachers and administrators alike reported that classroom use of Cognitive ToyBox was feasible, helpful and easy to use. Teachers also shared that the tool had the potential to better support their instruction, compared to previous assessment tools that they have used. Educators discussed the promise of the family engagement module if incorporated into the regular Pre-K program year. Finally, WestEd collected data from a third party tool for additional psychometric analysis, and CTB showed moderate to strong reliability and validity with this sample. Findings from this implementation study show that CTB holds promise in being a valuable tool for formative assessment in stand-alone center-based Pre-K settings. With the industry-wide workforce shortage, it could be an especially helpful tool in saving teachers time and providing scaffolding to support newer teachers in assessing school readiness with fidelity. (author abstract)