The goal of this study is to examine fatal overdoses among people who have experienced incarceration in Los Angeles County between 2014 and 2022 by (a) merging data from the Los Angeles Sheriff’s Department (LASD) on their jail bookings and releases with data from the Los Angeles Coroner’s office on fatalities in the county, and (b) conducting both descriptive and case-crossover analyses. Specifically, we are interested in four related research questions: (1) Among people who have experienced incarceration at some point during this period, how has risk of overdose and the types of substances involved changed over time? (2) Are people who have experienced incarceration during the period from 2014 through 2022 more likely to experience fatal overdose in the 30 days following jail release than in other time periods covered by the dataset (e.g., before any incarceration or >30 days post-release from jail)? (3) Is the risk of fatal overdose associated with length of stay in jail? (4) Are there differences in risk of fatal overdose by age group, race/ethnicity, sex, or type arrest charge?