After a review of nearly a dozen local, state, and national approaches to estimating the cost for ECE services, five approaches were selected for review. We chose models based on our assessment of their relevance to current public policy discussions and for their attempt to estimate costs for a system (see Table 1). We did not consider models that focused only on a restricted set or type of programs -- for example, we do not include an estimate of preschool services using the Preschool Quality and Revenue Calculator (CEELO, 2018) -- nor did we consider models that are not published for public consumption or generic cost-modeling templates. This brief highlights key features of the five models with particular attention to both the scope of services, workforce qualifications, and compensation as these are the major drivers of cost. Three of the selected models estimate national costs of services for children from birth to kindergarten entry, each with varying configurations, and the two selected state/regional models each represent different scopes of services and age of children, as well. (author abstract)