The present report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) Project compares patients with borderline personality disorder (BPD) in an outpatient practice (n = 390) and a partial hospital setting (n = 358) on diagnostic comorbidities, symptoms experienced, suicidality, and occupational impairment. The patients in the partial program were diagnosed with significantly more psychiatric disorders and were more frequently diagnosed with dysthymia, generalized anxiety disorder, alcohol and substance use disorders, adjustment disorders, and posttraumatic stress disorder. Those at the partial hospital had significantly higher levels of suicidal ideation than those in the outpatient practice. The samples did not differ on utilization of disability or suicide attempts. Treatment setting may have implications in the recognition of the disorder in clinical practice, the development and support of etiological theories, identification of core deficits, and evaluation of psychosocial morbidity associated with BPD.