Enhancing Delivery of Parenting Support within a Peer Recovery Support Service Model - Project Summary/Abstract Parental substance use disorders (SUDs) disrupt the parent-child relationship, resulting in detrimental effects for both parental recovery and long-term child health, behavior, and development. While parenting stress may be a potent trigger for drug cravings and relapse among parents with SUDs, with adequate support the parent- child relationship can serve as a source of joy, purpose, and an important motivator to seek recovery. Family- focused peer recovery support service (PRSS) has emerged as a potential approach for providing comprehensive support to families affected by SUDs. However, the PRSS model faces challenges to achieving the full bigenerational benefit for families because peer support specialists often struggle to deliver parenting support in this context. We propose tailoring an implementation strategy bundle aimed at improving delivery of evidence-based parenting support for a peer recovery support specialist audience. The multilevel implementation bundle, called Relational Health Enhanced Parenting support (RHEP), includes training, consultation, and implementation blueprint mapping to help overcome barriers to the delivery of parenting support. Building upon a longstanding community-academic partnership, we will collaborate with the Massachusetts Department of Public Health (MDPH) and their specialized home visiting program FIRST Steps Together (FST) to test RHEP. FST is centered on the family-focused PRSS model and is delivered at six sites across the state. RHEP-enhanced implementation of parenting support has the potential to amplify the ongoing work of FST peer staff by truly integrating parenting and recovery supports within a scalable model. In Phase 1 (R61), we will refine RHEP training and consultation materials and procedures for the PRSS model and workforce with engagement from our community partners. Furthermore, we will co-create an agency-level implementation blueprint for FST, operationalized via a tailored Stages of Implementation Completion® tool to evaluate the implementation process. In Phase 2 (R33), we propose a hybrid stepped-wedge cluster randomized design with six sites to test the effectiveness and implementation of FST plus RHEP. We will: (Aim 1) Determine the effectiveness of FST alone versus FST plus RHEP to improve parenting-related factors, SUD treatment retention, and reduction in substance use; (Aim 2) Investigate variation in the implementation process across sites to inform future dissemination; and (Aim 3) Examine the unique impact of peer staff on implementation and effectiveness outcomes. Upon completion of this study, we will have gained key insights into the delivery of effective support for parents in recovery and into critical factors influencing peer workforce development, and we will produce an implementation toolkit to facilitate dissemination of parenting support across peer-led non-clinical models of care.