Low-income and ethnically diverse youth in the United States have unmet needs for mental health services; however, these same youth are unlikely to be connected with high-quality mental health care. Promoting social-emotional competencies through school-based service delivery is one potential solution for improving the accessibility and quality of care for diverse youth facing mental health disparities. Mindfulness, conceived as a set of practices to cultivate social-emotional competencies, can therefore be useful for improving the accessibility and quality of care for diverse youth facing mental health disparities. Given the growing interest in MBSIs and the need to enhance equity in youth mental health services more generally, we provide guidelines to help practicing clinicians successfully adapt and implement MBSIs with underserved youth. First, we offer recommendations for clinicians to enhance underserved youths’ engagement with MBSIs. Next, we overview implementation approaches that clinicians could use for increasing access to MBIs in school settings. Following, we discuss strategies clinicians might employ when working with teachers to effectively implement MBSIs with underserved youth in their classrooms. Ultimately, we hope the guidelines offered in this paper might help inform better practice—as well as motivate further, better research—that advances equitable mental health care in schools with underserved youth.