Too often, people reentering the community from incarceration experience fatal overdoses, with studies showing that they are at a highest risk of an overdose or even death during the first 48 hours after release. This is typically related to a decrease in tolerance while in prison or jail, so their body is more vulnerable to overdosing even when using at the same amount they did before they were incarcerated. This risk is highest among people using opioids. Fortunately, there are evidence-based practices that can be implemented to support safe and successful transitions. This guide outlines four best practices that reentry professionals can implement to reduce overdose risk during reentry.