This purpose of this Research Brief is to analyze trends and general patterns of student in-grade retention among students in grades K-8 within the Miami-Dade County Public School (M-DCPS) for the 2022-2023 school year. While in-grade retention in grades 9-12 may occur due to the lack of credit in one or more courses, students often recover these credits in the summer, through online studies, or in subsequent grades. In addition, senior high schools have an incentive of graduating students within four years after they enter grade 9 because the high school graduation rate is used as a component in the school grade calculations. Because of the existence of the State's mandatory retention law (Florida Statute 1008.25) that stipulates conditions for mandatory retention in grade 3 and describes good cause exemptions from that requirement, retention in grade 3 is qualitatively different from any other grade. In fact, more than one-half (51%) of all 2022-2023 retained students in grades K-8 in M-DCPS were retained in grade 3.