We assessed the impact of compulsory kindergarten education on early teenage basic and functional literacy skills achievement using a large-scale natural experiment in the Philippines. In 2012, the Philippine government mandated compulsory kindergarten attendance for children aged five years or older prior to enrolling in the country’s basic education cycle. This created a non-trivial discontinuity in the propensity of kindergarten school attendance among different cohorts of children, which we exploited in this study. We find that children who were exposed to the policy were no more likely to be able to read, write and calculate by age 11–13 years when contrasted with comparable peers who were not compelled to attend kindergarten. However, those who were exposed to the policy were more likely to reach full functional literacy by early teen-age, which is likely due to dynamic complementarities in skills formation. While other children were able to eventually catch up with basic literacy skills in later childhood, children who attended kindergarten were more likely able to read and write before entering primary school, which likely allowed them to develop further skills later.