Project Summary The overarching goal of this study is to evaluate a high-volume, low-threshold, naloxone-on-release program serving individuals being released from the Los Angeles County Jail system. Opioid-related overdose death is the single largest cause of accidental death in the United States. Individuals being released from incarceration are at particular risk, with some studies showing their risk of death in the weeks immediately after release is as much as 129 times that of the general population. One intervention demonstrated to reduce opioid-related deaths is training opioid users and those in their immediate social circles to recognize overdose and to respond by using naloxone, an opioid antagonist which effectively ‘reverses’ overdose. Overdose Education and Naloxone Distribution (OEND) programs are now present in almost every state. However, access to OEND programs has not been equitable, with African American and Latinx people who use opioids being less likely to access OEND, a particular concern given opioid-related overdose mortality has increased 114% among Black and 97% among Latinx populations over the last 5 years compared to 32% among Whites. One recent innovation, ‘naloxone-on-release’, aims to address the particularly high rate of overdoses experienced by individuals being released from incarceration. In addition, naloxone-on-release has the potential to reach populations underserved by traditional OEND programs given the over-representation of African American and Latinx people in incarcerated populations nationwide. At least 28 pilot or early stage naloxone-on-release programs currently exist in the US, however to date the literature on these programs is largely limited to descriptions of feasibility and logistical issues. A single paper describes the efficacy of a national-level program in Scotland, which, encouragingly, saw a 36% drop in the proportion of overdose deaths among releasees in the four weeks following release. In January 2020 the Los Angeles Sheriff’s Department implemented a naloxone-on-release program, in which all inmates being released from the LA County Jail system are exposed to a video training on overdose recognition and response and are able to take as many doses of naloxone as they wish from a no-cost vending machine at the point of release. 31,352 doses of naloxone were distributed by the program in 2020, almost twice as much as every other OEND program in Los Angeles combined, and making it by far the largest such program in the world (the Scottish program described above distributed 2,273 doses over 3 years). We will use an innovative mixed-methods design to capitalize on this timely opportunity, and examine whether the naloxone-on-release program is serving those most at risk, whether the program reaches previously underserved populations, how the program impacts the communities to which releasees return, and whether the program reduces deaths among releasees and in the communities to whic...