Researchers have raised concerns about parental migration's effects on various aspects of the left-behind children's development. However, there is limited understanding of how parental migration influences children over the life course. This study aimed to fill this gap by investigating how exposure to parental migration during childhood shapes later development in Indonesia and the Philippines, two major labor-sending countries in Southeast Asia. Adopting a life course perspective, we examine how the timing, sequence, and cumulative extent of parental migration affect children's outcomes. We used longitudinal data from 1,023 households in 2008 (with children aged 4.56 on average) and 849 households in 2016/17 (with children aged 12.78 on average). Retrospective information on children's exposure to parental migration during early childhood (under 3), middle childhood (4-5), and late childhood (6-10) was constructed for its impact on individuals' school performance and psychological well-being during early adolescence (11-14). The findings indicate that the timing of children's initial exposure to parental migration impacts certain aspects of their development. In Indonesia, paternal migration during middle or late childhood is associated with a trade-off between improved school performance and reduced prosocial behavior. For Filipino children, maternal migration during the first 3 years is linked to higher levels of internalizing problems, while migration during middle and late childhood reduces the risk of such problems. These findings underscore the importance of tailored policies and support programs that acknowledge the diverse impacts of parental migration across different developmental stages, considering distinct cultural contexts. (PsycInfo Database Record (c) 2025 APA, all rights reserved).