Key PointsQuestionWas the COVID-19 pandemic associated with changes in psychiatric boarding among publicly insured youths who were initially evaluated by a mobile crisis team?FindingsIn this cross-sectional study of 7625 psychiatric emergency services encounters, publicly insured youths evaluated by mobile crisis teams were 2 times more likely to experience psychiatric boarding, and boarding youths were 64% less likely to be discharged to inpatient psychiatric care during the pandemic.MeaningThese findings suggest that psychiatric service programs were not prepared to support the levels of acuity and demand from youths that emerged during the pandemic.