This data brief presents a model of school psychologist turnover based on publicly available datasets. The model calculates the difference between the expected number of school psychologists for a current year by adding the number of school psychologists from the previous year with estimates of incoming graduates who work in schools. The number of school psychologists for that current year are then subtracted from the estimated total. This provides the estimated raw number of school psychologists who left the field in any given year. To obtain a percentage change that can be compared with other professions, the raw number of school psychologists who left in that year was divided by the current year's total number of school psychologists. Based on this model, the rate of turnover for the 2020-2021 school year was 6.7%. The model is presented in more detail, and the implications of the model are discussed in this paper.