Objective: Despite a greater need for mental health treatment in individuals identifying as lesbian, gay, bisexual, queer, and other sexual minority identities (LGBQ+), no prior study has examined mental health treatment outcomes for LGBQ+ populations receiving standard care. We compared individuals identifying as LGBQ+ or heterosexual on treatment outcomes following a partial hospital program based on cognitive behavioral therapy (CBT) and dialectical behavior therapy (DBT). Method: A total of 441 participants (19% LGBQ+; mean age = 34.42 years; 56% female, 42% male, 2% nonbinary) attending a partial hospital program completed measures at admission and discharge as part of standard care. We compared LGBQ+ and heterosexual individuals on symptom outcomes (24-item Behavior and Symptom Identification Scale, 7-item Generalized Anxiety Disorder Scale, 9-item Patient Health Questionnaire), program dropout due to inpatient hospitalization, clinical global improvement, and perceived quality of care, controlling for baseline characteristics using propensity score adjustment. Results: Controlling for baseline demographic and clinical variables and a 10% false discovery rate, LGBQ+ and heterosexual individuals did not differ on treatment outcomes. However, when examining sexual identity subgroups, bisexual individuals reported more self-injurious and suicidal thoughts and worse perceptions of care at posttreatment compared to all other sexual identities. Conclusions: Findings support the comparable effectiveness of CBT- and DBT-skills-based hospital treatment for LGBQ+ and heterosexual individuals overall but suggest specific treatment disparities for bisexual individuals. Future research is needed to establish the effectiveness of traditional evidence-based treatment in other settings and to determine whether LGBQ+ affirmative treatments for specific LGBQ+ subgroups are superior to traditional treatments.