This study reviews the current status of Korean first graders, their experience with early care and education (ECE) programs, and their participation in private and after-school education. The research also examines how school adjustment during the first grade is related to family income, types of ECE programs, and participation in private and after-school education. Using the first year data of the Korean Child and Youth Panel Survey (KCYPS) 2010, this study analyzes 752 first graders who attended only one of two types of ECE programs (child care centers or kindergartens), after which two 25% income extremes were examined. The analysis demonstrates that children from low-income households attended child care centers more often, while children from high-income households attended kindergartens more often. For both low-income and high-income groups, child care centers had a lower starting age and longer attendance periods than did kindergartens. High-income household children started attending ECE programs earlier, experienced more private and after-school education, and received a larger number of private and after-school educational lessons. For the second research purpose, children from low-income families showed better peer relations in school adjustment, while children attending child care centers showed better teacher relations than children attending kindergartens. Children with after-school education also exhibited better peer relations. These findings show the importance of government support for early learning, especially for low-income families and offer a foundation for developing private education polices for early childhood before and after school entry.