Abstract Objective To investigate patterns of mental health service and antipsychotic use following a first-episode schizophrenia (FES) and to examine the role of the treatment setting in which individuals are first diagnosed. Method Analysis of de-identified administrative claims data from the OptumLabs Data Warehouse was used to identify 1450 privately insured youth and young adults aged 14 through 30 with FES from January 1, 2011 through December 31, 2015. Regression analysis was used to estimate the use of mental health services during the year following FES, by type of service and by site of index diagnosis. Results In the year following FES, 79.7% of youth received outpatient mental health services and 35.8% filled a prescription for antipsychotic medication. Among service users, mean outpatient visits were 15.9 and mean antipsychotic fills were 8.3. Youth who received an index diagnosis of FES in an inpatient setting were more likely to fill an antipsychotic medication than youth with FES in other settings. Youth who received an index diagnosis of FES during a specialty mental health outpatient visit had greater use of outpatient mental health than youth who received their diagnosis during a primary care visit. Conclusions Despite evidence-based guidelines supporting outpatient psychosocial care and antipsychotic treatment for FES, one-fifth of this cohort did not use outpatient services and the majority did not fill any prescriptions for antipsychotic medications during the year following FES. Our findings provide renewed urgency to ongoing efforts to accelerate early identification and care coordination for youth with FES.