This study investigated the long-term impact of the science writing heuristic (SWH) approach on students' science achievement, focusing on differences between low and high socioeconomic status (SES) groups. Through a longitudinal design, students were divided into control and treatment (at least 1 year of SWH) groups. Polynomial growth mixed modeling analyzed longitudinal data from Grades 4 to 11 using Iowa Test of Basic Skills scores. Results showed that younger students in the SWH approach had better achievement growth, and the SWH experience affected science achievement differently for students from low and high SES backgrounds. The findings support the importance of early intervention for disadvantaged groups, such as students from low SES backgrounds.