The Peer Offender Prevention Service (POPS) program was established in 2009 at Stony Mountain Institution (SMI) as a peer-based mental health first response program. Members of POPS program are on call 24/7 to provide support, counselling, mentoring, and guidance to inmates at all security levels in the institution (maximum, medium and minimum), including within the institution’s Structured Intervention Unit (SIU). Consultations were held with inmates and staff at the institution to understand program impacts and ingredients to sustained success.