OBJECTIVES: Follow-up after hospitalization for mental illness is a standard HEDIS (Healthcare Effectiveness Data and Information Set) quality indicator that may affect risk of relapse.  This study evaluated rates of follow-up visits and implications for re-admissions for patients with schizophrenia or bipolar disorder using administrative claims data. METHODS: A cross-sectional analysis of Optum Clinformatics data (1/1/2013–12/31/2013) was completed for two cohorts – schizophrenia (with or without bipolar) and bipolar only.  Schizophrenia patients were required to have ≥1 inpatient or ≥2 outpatient claims for schizophrenia and ≥1 antipsychotic medication claim.  Bipolar patients were required to meet the same criteria and also be≥18 years old.  Patients were identified as having follow-up after a psychiatric-related hospitalization if they had an outpatient visit with a psychiatric diagnosis within 7 days of discharge of each psychiatric hospitalization they had in the analysis period. Logistic regression analysis was undertaken to assess the effects of a 7-day outpatient follow-up visit on likelihood of readmission, controlling for age, sex, substance abuse, other psychosis, antipsychotic MPR, and use of antidepressants, anxiolytics, anticonvulsants, and mood altering drugs. RESULTS: The schizophrenia cohort (N=4,164) had mean (SD) age of 36.9 years (15.6), 51.2% had other psychosis, and 43.2% had a psychiatric hospitalization.  The bipolar cohort (N=21,768) had mean (SD) age of 40.0 years (13.1), 40.0% had other psychosis, and 28.0% had a psychiatric hospitalization.  Among patients with ≥1 psychiatric hospitalization, 30.3% and 32.9% had outpatient follow-up visits within 7 days in the schizophrenia and bipolar cohorts, respectively.  Using multivariate analysis, patients with follow-up within 7 days of discharge had a >50% reduction in likelihood of 30-day re-admission in both cohorts (Schizophrenia: OR=0.40; 95% CI=0.31-0.51; p<0.0001 and Bipolar: OR=0.46; 95% CI=0.41-0.52; p<0.0001). CONCLUSIONS: Outpatient follow-up within 7 days after hospitalization for mental illness was associated with statistically significant lower likelihood of 30-day re-admission.