The current early care and education (ECE) policy context is bringing increased attention to the training completed by the child care workforce and to the use of registries to track such training. Although ECE workforce registries are designed to record individuals' data, aggregate registry data have the potential to shed light on the workforce's training needs. However, to date, registries have not been tapped in this way, and there is limited research on the data collected across registries and the extent to which they are standardized. In this report, I share the results of research on the training focus variables used across these databases and on the extent to which such variables are comparable. Also explored is when registries began recording these data and whether enrollment is voluntary, incentivized, or mandatory. The results of the study suggest that aggregate registry data have the potential to address questions related to the focus of the training in which the ECE workforce participates. However, additional research on ECE workforce registries is needed to confirm their usefulness as a source of data on child care training as well as the accessibility of these data.