EDC's Regional Educational Laboratory Northeast and Islands worked with state and district practitioners to develop the Home Language Survey Data Quality Self-Assessment Tool. This 15-minute self-assessment is designed for use by state leaders who coordinate programs to support students’ English language acquisition and achievement in districts, as well as for district leaders who oversee the English learner student identification process in schools. The tool supports the collection of high-quality home language survey data by gathering information from district English learner student coordinators and prompts self-assessment of key practices that impact the quality of home language survey data. The report includes a guiding Data Quality Framework and presents the complete self-assessment tool along with description of how it was developed, how to adapt and administer the self-assessment, and how to engage stakeholders in analyzing and interpreting self-assessment results to identify opportunities for improvement. This engagement at both state and district levels will inform decisions that can contribute to the collection of more accurate data regarding English learner students.