Pennsylvania Pre-K Counts (PA PKC) is a state-funded prekindergarten program for 3- and 4- year-old children to help them gain school readiness skills. The goal of PA PKC is to help reduce educational disparities by providing high quality prekindergarten for children who lack opportunities or reside in environments that place them at risk of school failure. This Impact Study examined the effects of participation in PA PKC on children's early academic, social, and executive function skills in kindergarten. In particular, the study focused on whether there were differences in performance for children with 1 or 2 years of enrollment in PA PKC compared to children with no early childhood education (ECE) experience in the 2 years prior to kindergarten. Two primary research questions (1 and 2) guided the study to examine the effects of participation in PA PKC. A third research question (3) examined potential moderators, or factors that might have an influence on any effects found for program participation: (1) Do children who attended PA PKC have higher levels of academic and social skills in kindergarten than children with no prior preschool experience?; (2) Are kindergarten skills different for children who attended PA PKC for 1 year (enrolling at age 4) or 2 years (enrolling at age 3)?; and (3) Are there differences in the effects of PA PKC based on various program characteristics -- percent of 3-year-olds served, region of the state, or level of urbanicity/rurality? In sum, the results of this evaluation demonstrate positive benefits on language and math skills in kindergarten for children who attended PA PKC compared to similar children with no prior ECE experience in the 2 years before kindergarten. Thus, it would appear that PA PKC is well suited to promote key school readiness skills known to predict later reading and academic success. [This report was prepared by the University of North Carolina at Chapel Hill, School of Education. Additional funding was provided by the BUILD Foundation.]