This study explored the relationship between tablet/computer use for at-home schoolwork and reading achievement using 2016 U.S. data from the Progress in International Reading Literacy Study. Multilevel analysis revealed that weekly and daily users had lower reading achievement than non-users, with gender moderating these associations. Subgroup analyses demonstrated that monthly users in the advanced-performing group had higher reading achievement than non-users, while daily users in the high-performing group had lower reading achievement. We suggest personalized support for primary school students, tailored to their reading proficiency, to improve their device use for at-home schoolwork and enhance their reading abilities. This research advances our understanding of the intricate relationship between digital device use and reading achievement, providing insights for educational stakeholders.