This fifth article of the Social Justice Committee's series on health disparities expands on previous articles (i.e., Tan et al., 2020; Ormiston et al., 2021) to discuss applications of advocacy by school psychologists to improve health parity for youth. As previously outlined in Proctor et al. (2020), health disparities are restricted opportunities to access healthcare and differences in the prevalence of avoidable physical and mental health concerns (e.g., disease, disorder diagnoses, treatment efficacy) that disadvantage marginalized populations. From a social justice perspective, school psychologists must recognize these disparities, the impact they have on the lives of children and families, and actively work to address individual and systemic factors (see, e.g., Sullivan et al., 2020) that contribute to the lack of parity in health outcomes for minoritized populations. To help further illustrate the need for, and steps in, integrating an understanding of social justice as it applies to health disparities, the authors spotlight inequities in healthcare experienced by students with intellectual and developmental disabilities (IDD). [For the fourth article in the series, "Social Justice as a Framework for Addressing Mental Health Disparities," see EJ1282396.]