ABSTRACT Suicide is the second leading cause of mortality among adolescents and young adults (AYA) and rates of suicide and emergency department visits for suicide attempts have been increasing in this age group over the past decade.1-3 Outpatient medical settings may serve as a safety net to improve the detection, management, and outcomes for AYA with suicidal ideation.4-8 Improving outcomes requires interventions and tools that are designed for implementation in the fast-paced outpatient medical setting. Practice guidelines and toolkits recommend that a positive suicide screening be followed by a full assessment and safety planning.9-11 However, healthcare providers in outpatient medical settings have few supports to complete this work. In this R34 application, we propose to use Human-Centered Design strategies12 with AYA, parents, and healthcare providers to build and optimize an Integrated Screening and Safety Planning (ISSP) tool for AYA who screen positive for suicidal ideation in pediatric outpatient medical settings. The tool will include: 1) safety assessment, 2) algorithms for risk stratification and decision support for HCPs to guide next steps of care, 3) integrated tools for collaborative safety plan completion with means restriction counseling, and 4) creation of a registry to improve tracking and follow-up. We then conduct a pilot study with 100 AYA (ages 13-21) in three outpatient clinics, comparing use of the ISSP tool to the usual care Seattle Children's clinical pathway on the primary outcomes of AYA Suicide-Related Coping, Parent Suicide Prevention Self-Efficacy, and Provider Suicide Management Self-Efficacy using a pre-post design. Parents and AYA will complete surveys at baseline, and 1- and 2-month follow ups, and healthcare providers will complete surveys at three time points: prior to the control period, after the control period, and after the intervention period. ISSP provides the opportunity to engage stakeholders and co-design technology that addresses a key challenge in the assessment of suicidal ideation in medical settings: moving beyond screening to a focus on improving the completion of screening in a way that empowers AYA, HCPs and parents. If successful, this tool has the potential for future broad dissemination including adaptations to other medical settings and for use with other age groups. A key strength of our proposal is the focus on implementation needs alongside intervention development which will shorten the timeline for tests of efficacy in an R01 trial as well as future dissemination efforts.