Patterns of reinstitutionalization following psychiatric hospitalization for individuals with serious mental illnesses (SMI) vary by medical and psychiatric health care settings. This report presents rates of reinstitutionalization across care settings for 35,527 patients following psychiatric discharge in the Department of Veterans Affairs (VA) health system, a national health care system. Over a 7-year follow-up period, 30,417 patients (86%) were reinstitutionalized. Among these patients, 73% were initially reinstitutionalized to inpatient psychiatric settings. Homelessness, medical morbidity, and substance use were associated with increased risks for reinstitutionalization. Despite the VA's increased emphasis on outpatient services delivery, the vast majority of patients experienced reinstitutionalization in the follow-up period. Study findings may inform efforts to refine psychiatric and medical assessment for service delivery for this vulnerable population.