Avident Health, in partnership with MedStar Health Research Institute (MHRI), will develop the MyNavigator mHealth App and conduct a usability study for breast cancer Patient Navigators (PNs) and their patients. Objectives: (1) develop an Minimum Viable Product (MVP) that increases PN operational efficiencies, facilitates seamless communications, collaboration, and knowledge transfer between PNs, patients, patients’ families, and caregivers; (2) obtain PN, patient, and clinician feedback, and (3) integrate MyNavigator with Electronic Health Records. Specific Aims: (1) establish feasibility as a tool for PNs, (2) build a human-centered design prototype, and (3) test effectiveness among 25+ users. Research Design & Methods rely on Project Management best practices, establishing a need using the York Method for literature reviews, Agile software development for solution development, and heuristic evaluation for usability. Formative and summative testing will be completed upon MVP development at MedStar Health facilities. Technological Innovation includes leveraging Avident’s existing intellectual property, which is protected by two patent applications, and creating a brand new tool to identify and serve the needs of PNs. Expected results: (1) MyNavigator refined utilizing stakeholder focus groups and validated with survey data and quantitative back-end app data. (2) MyNavigator improves communication and patient engagement while reducing cancer care team patient anxiety.