The primary website for checking middle school grades in the United States is the student's school district's official website. This platform provides access to grades and academic records for students enrolled in middle schools within the district. The use of district-specific websites is widespread due to the varying policies and systems in place across different regions. According to a report by the National Center for Education Statistics (NCES), approximately 80% of school districts in the U.S. have online portals for student information, including grades (NCES, 2020). These portals are designed to enhance communication between parents, students, and educators, ensuring that grades are readily accessible and transparent.