Oral atypical antipsychotic (OAAP) medications are the most commonly prescribed treatment for the management of schizophrenia symptoms. This retrospective study, using Medicaid claims data (2016-2020), followed patients for 12 months after initiating OAAP therapy. Study outcomes included OAAP adherence, switching, augmentation, healthcare resource utilization (HRU), and expenditures. All-cause and schizophrenia-related HRU and expenditures were compared between adherent and nonadherent cohorts. Among 13,007 included patients (39.1 ± 12.8 years of age, 57.0% male, 36.1% Black, 31.8% White, 9.7% Hispanic), 25.7% were adherent to OAAPs (proportion of days covered [PDC] ≥ 0.8). During the 1-year follow-up period, Black individuals were in possession of an OAAP for an average of 166 days compared to 198 and 202 days for White and Hispanic patients, respectively. Approximately 16% of patients switched OAAP medications and 3.2% augmented therapy with an OAAP added to their index medication. Nearly 40% of patients were hospitalized during follow-up and 68.4% had emergency department (ED) visits. A greater proportion of nonadherent patients had all-cause inpatient (41.7% vs. 34.1%, p < 0.001) and ED visits (71.7% vs. 58.8%, p < 0.001) compared to adherent patients. Annual total healthcare expenditures were $21,020 per patient; $3481 higher for adherent versus nonadherent patients. Inpatient expenditures comprised 44.6% and 30.6% of total expenditures for nonadherent and adherent patients, respectively. Hospitalized patients' total expenditures were $23,261 higher compared to those without a hospitalization. Adherence to OAAP medication is suboptimal and associated with increased utilization of costly hospital and ED resources. Efforts to improve therapies and increase medication adherence could improve clinical and economic outcomes among individuals with schizophrenia.© 2023. The Author(s).