Evidence of longitudinal relations between language and early literacy skills in early childhood and later reading (and other) achievement is growing, along with an expanding array of early education programs designed to improve later academic outcomes and prevent, reduce, or close later academic achievement gaps across groups. Assessment systems to support this intervention have been developed, but to date we have little evidence of these systems’ outcomes when used at a broad scale in community-based preschool programs. For this broad purpose, two research questions were addressed: (a) How much progress do children make on language and early literacy skills over the course of one school year? and (b) What is the relationship between child characteristics, baseline performance, and growth on language and early literacy skills? Results indicated growth over time for all measures and relations between child age, gender, and free-or-reduced price status and students’ performance at the beginning of the school year, but (with one exception) no relation between these covariates and growth over time. Discussion centers on current status of language and early literacy assessment in early childhood education as well as needs and issues to be addressed in future research and program development. (author abstract)