No consensus exists about which medical testing is indicated for youth with new-onset psychotic symptoms. We conducted a chart review of youths aged 7-21 years who were medically hospitalized for workup of new-onset psychotic symptoms from January 2017 through September 2020 in a free-standing children's hospital. The sample included 131 patients. At discharge, 129 (98.5%; 95% confidence interval [CI]: 94.5-99.8) were diagnosed with a primary psychiatric condition, 1 was diagnosed with levetiracetam-induced psychosis, and 1 with seronegative autoimmune encephalitis. Notably, 33 (25.2%; 95% CI: 18.0-33.5) had incidental findings unrelated to psychosis, 14 (10.7%; 95% CI: 6.0-17.3) had findings that required medical intervention but did not explain the psychosis, 12 (9.2%; 95% CI: 4.8-15.5) had a positive urine drug screen, and 4 (3.1%; 95% CI: 0.8-7.6) had a neurological exam consistent with conversion disorder. In conclusion, extensive medical testing in the acute setting for psychosis had a low yield for identifying medical etiologies of new-onset psychotic symptoms.