This toolkit offers an overview of the opioid problem and how OST programs and communities can respond. Part I includes an introduction to the opioid crisis, along with assessment and planning tools for designing a prevention initiative based on local needs. Part II provides a menu of prevention strategies–for staff, youth, families, and school and community partners–that could be included in a plan, and resources to help with implementation. The suggested strategies support positive youth development and social-emotional learning, in general, so could be adapted for other content too (e.g., pregnancy prevention). This resource supports resiliency.