Background: We examined trends in mental health service utilization before, during, and in the immediate return to in-person learning throughout the COVID-19 pandemic. Methods: Retrospective chart review was assessed for changes in odds of any visit being a mental health encounter from five school-based health centers from the 2018-2019 to the 2021-2022 school years. Data are limited to the in-person school year from mid-August to early June. Results: Data were assessed from 1239 students seen through 2256 visits over the 4 school years (M[subscript age] = 12.93). The odds of any visit being related to a mental health encounter increased each school year, with the 2020 to 2021 and 2021 to 2022 school years having significant increases in odds (both compared to the first and to the antecedent school year). In addition, during the 2019 to 2020 and 2020 to 2021 school years, the odds of a repeated mental health encounter significantly increased from year to year. Conclusions: Findings indicate a steadily increasing number of mental health service utilization needs among adolescent students that was significantly exponentiated throughout the COVID-19 pandemic.