Collecting data on lesbian, gay, bisexual, transgender, queer-plus (LGBTQ+) issues and the experiences of LGBTQ+ young people is essential both for enforcing civil rights protections and advancing racial, gender, and disability justice outcomes in K-12 education systems across the country. The absence of this data: (1) Is a barrier to full implementation of nondiscrimination protections; (2) Obscures disparities impacting LGBTQ+ young people in K-12 schools; Prevents educators from accessing the information they need to develop and evaluate the impact of programming on LGBTQ+ students and their non-LGBTQ+ peers; and (3) Limits the ability to assess the impact of laws, policies, and initiatives on the health and wellbeing of LGBTQ+ young people and young people with an LGBTQ+ parent, guardian, or family member. Leading scientists, researchers, and educators agree on the need for LGBTQ+ data inclusion. This brief explains why LGBTQ+ data inclusion is necessary to ensure all students have access to safe and inclusive schools and details policy recommendations for LGBTQ+ data inclusion in different contexts, such as: (1) School climate surveys administered by schools or local education agencies, including as part of statewide accountability system; (2) Surveys of teachers, administrators, and other staff; (3) Surveys of parents and families; (4) Federal surveys of young people in K-12 schools, including the Youth Risk Behavior Survey and the High School and Beyond longitudinal study; and (5) Administrative data collection, including the U.S. Department of Education's Civil Rights Data Collection.