By focusing on a period of a major public childcare expansion in Germany, this study investigates whether higher levels of childcare coverage for under-threes have been positively associated with employment among mothers with different educational backgrounds. Both standard economic labour theories and sociological theories presume that the effect of public childcare provision varies with mothers’ educational attainment. The analysis links county-level data on annual childcare ratios with individual-level data from the Socio-Economic Panel Study (2007–2016). To match mothers with similar characteristics in counties with childcare ratios above and below the annual median within East and West Germany, entropy balancing is applied. Findings indicate a positive relationship between childcare provision and maternal employment, with more pronounced associations for mothers with at least a vocational degree, those with a second birth and those who receive full-time access to childcare.