This study examines the effects over time of implementing the William and Mary language arts and science curriculum for gifted learners designed around the Integrated Curriculum Model (ICM) in one suburban school district. It also analyzes stakeholders' perceptions of the effectiveness of the curriculum. Findings suggest that gifted student learning at grades 3 to 5 has been enhanced at significant and important levels in language arts critical reading and persuasive writing and scientific research design skills, through the use of the curriculum across individual academic years and over a period of 6 years. Repeated exposure over 2- to 3-year periods across cohort groups demonstrated strong increasing achievement patterns. The majority of all stakeholder groups found the curriculum to be effective and beneficial in very specific ways.