A semi-structured diagnostic interview was was administered to 2,122 patients attending a partial hospitalization program; 69 of the patients identified themselves as transgender, genderqueer, and of non-binary. Among the patients, transgender and gender diverse patients were diagnosed with a greater number of psychiatric diagnoses than cisgender patients (3.54 vs. 3.04), and were more frequently diagnosed with posttraumatic stress disorder and borderline personality disorder compared with cisgender patients. These results highlight the importance of expertise in treating these conditions for providers working with transgender and gender diverse persons.