Practicing elements of affirmative psychotherapy for LGBTQ+ clients is not merely a provider preference; rather, pursuing fair and equitable treatment is a foundational part of providing ethical psychotherapeutic care to any client population. This chapter is designed to help clinicians become more comfortable with practicing identity affirmation with LGBTQ+ clients, and this goal is intertwined with the objective of empowering clients to self-affirm, explore, and develop their gender and sexual identities. Identity affirming care is paramount for promoting positive mental health outcomes in LGBTQ+ populations. Clinicians are also bound by an ethical duty to provide affirmative care for LGBTQ+ clients. The overarching goals of this chapter are to: a) review the theory, research, and clinical applications of identity development and affirmation; b) discuss specific existing interventions and empirical factors that promote LGBTQ+ affirmation and highlight considerations for marginalized subgroups, and c) apply theory by illustrating what affirmation and identity development may look like in a clinical setting through a case study.