Postpartum depression (PPD) represents the most frequent cause of postpartum morbidity for mothers. PPD also impairs maternal-infant interactions, often contributing to poor developmental outcomes for children. Recent evidence suggests that telephone-based peer support can help prevent mothers’ symptoms of PPD. In this descriptive qualitative study, integrated knowledge transfer (IKT) and implementation science approaches were used to: (1) adapt a research model of telephone-based peer support designed to prevent PPD symptoms into an intervention program to treat PPD symptoms and (2) integrate telephone-based peer support to treat PPD into the real-world health service delivery setting. IKT involved extensive partnership with a provincial government of a Canadian province. Research questions included: What are the required characteristics of telephone-based peer support to: a) reflect contemporary research, b) seamlessly integrate with established provincial telephone support line technology, and c) operate in an innovative, effective, accessible, and sustainable manner? Qualitative individual (n=19) and group (n=2) interviews with expert stakeholders from service delivery, government, and consumer and advocacy associations were undertaken. Thematic analysis was employed to identify broad perspectives of the program’s training manual, training sessions as well as planned program content and delivery. Findings revealed a focus on improving clarity and inclusivity of the manualized content, lengthening and enriching training opportunities for peer mentors, and addressing program structure, sustainability, outreach and peer mentor selection and needs, including ongoing supervision and support. Findings were incorporated into program design. Thus, innovative implementation science and IKT approaches served to adapt and integrate telephone-based peer support into existing telephone support line technology, promoting accessibility to evidence-based programs for more mothers suffering from PPD.