This dissertation aims to elucidate that current school-based mental health services need a more LGBTQI+ affirmative stance to counter and disrupt the heteronormativity, homophobia, biphobia, and transphobia that LGBTQI+ students regularly encounter at school. Many LGBTQI+ students continue to be harassed, bullied, and discriminated against; school-based mental health providers must be knowledgeable about the protective factors and risks that contribute to the safety and mental health of LGBTQI+ students. School psychologists and other school-based mental health providers need to be prepared to support the unique needs of their LGBTQI+ students. The unique challenges that LGBTQI+ students experience directly affect their mental health, their overall well-being, and their school performance. This dissertation utilized an extended literature review approach to explore the unique experiences of LGBTQI+ students in K-12 and why it is imperative that school-based mental health providers adopt an affirmative stance when working with students who identify as LGBTQI+. School-based mental health providers are encouraged to incorporate Minority Stress Theory in their counseling practices by using an LGBTQI+ affirmative stance, supported by psychodynamic and object relations theory as a clinical framework to deliver mental health interventions. Based on this comprehensive literature review, it is recommended that a professional development series be created for school-based mental health providers that focus on LGBTQI+ mental health in middle and high schools. There continue to be significant gaps in knowledge regarding the educational paths of LGBTQI+ students, despite increased research on LGBTQI+ issues. Educational researchers must continue to grow the body of knowledge regarding how to support LQBTQ+ students in school settings. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]