Project Summary/Abstract Use of fentanyl and methamphetamine (MA) made 2021 the deadliest year ever for people using drugs in the United States (US). Intentional co-use as well as rising adulteration of MA with fentanyl elevate the risks and harms associated with MA use – the age-adjusted rate of drug overdose deaths involving psychostimulants (primarily MA) increased 10-fold between 2009 and 2019. Little is known about preventing overdoses involving MA or engaging people using MA in harm reduction and treatment. Strategies to engage people who use MA in harm reduction activities are essential. Contingency management (CM) uses rewards to incentivize behaviors and is the most efficacious strategy for improved retention in treatment and reduced stimulant use. Peer recovery support specialists reach people not seeking treatment to help them identify harm reduction goals and engage in treatment. The PEER-CM study combines both evidence-based interventions—CM and peer engagement--to decrease overdose and improve engagement in harm reduction services for people who use MA. Our network of peer harm reduction organizations is eager to identify optimal strategies for implementing Oregon’s recent approval of sustainable CM funding to reduce overdose. The PEER-CM study tests the effect of incentivizing achievement of self-identified, personal harm reduction goals compared with standard of care (peer harm reduction service with incentives for peer visits) to increase the reach and effectiveness of MA harm reduction services. A hybrid type 1 effectiveness-implementation framework and stepped-wedge design randomizes eighteen community-based peer harm reduction sites to provide standard of care (incentives for peer encounters) versus client achievement of self-identified, personal harm reduction goals. Peers assist clients in setting personal harm reduction goals using a client-driven harm reduction goal- setting process focused on completing harm reduction supply training, possessing harm reduction supplies, daily life goals, treatment and care goals, and relationship and social support goals. The CM intervention is rolled out at three-month intervals in the stepped-wedge design (2 peer sites at a time). Peers manage incentives and facilitate progress towards meeting self-identified goals. Aim 1 tests the impact of incentives for achieving self-identified, personal harm reduction goals on the likelihood of overdose among people using MA. Aim 2 determines whether incentives for achieving self-identified, personal harm reduction goals increase engagement with harm reduction and treatment services. Aim 3 completes qualitative interviews to understand the optimal context and implementation strategies for peer-facilitated contingency management. The PEER- CM study advances a patient-centered, sustainable, scalable, and innovative contingency management model to increase the impact of harm reduction delivered outside of traditional treatment networks and stem the ti...