Background: Chemotherapy and surgery can cause distressing symptoms, which can be a burden for health systems to address. Programs that directly engage patients, including electronic tracking of patient-reported outcomes (ePROs), can improve symptom control and decrease the need for acute care. Previous ePRO programs have relied on third party vendors with limited EHR integration, constraining their clinical utility and scalability. An integrated solution could offer distinct advantages. Methods: As part of NCI’s Moonshot-funded IMPACT consortium, 6 health systems and Epic built an electronic symptom management program (eSyM) based on the PRO-CTCAE questionnaire that is fully integrated into the EHR. The agile, user-centered design process engaged patients, clinicians, and institutions. The core functional components include: 1) symptom surveys in the postoperative period or between chemotherapy visits, 2) self-management tip sheets, 3) clinician alerts, and 4) dashboards for population management. Critical points of integration with supporting EHR functions and workflow impacts were identified; and major challenges of integration and implementation were described. Results: eSyM, which was implemented at two health systems (Baptist Memorial in Tennessee and Mississippi and West Virginia University Health) in the fall of 2019, required multiple supporting EHR functions: 1) access a secure, HIPPA-compliant patient portal/messaging system (MyChart); 2) record diagnosis, procedure and chemotherapy treatment plan data; 3) identify target populations and track metrics/events; 4) define and execute autonomous logic-based workflow rules; 5) generate reports for clinicians/patients; and 6) documentation. Major challenges included: 1) working within pre-existing EHR system standards and capabilities, which limited the ability to customize interfaces and workflows specifically for the eSyM use case; and 2) adapting to different EHR configurations and polices across multiple health systems. Conclusions: The eSyM build leveraged many existing EHR capabilities and overcame regulatory hurdles; but it required design and workflow compromise. Integration of ePRO-based symptom management programs into the EHR could help overcome barriers, consolidate clinical workflows, and foster scalability/sustainability. Ongoing efforts include launching eSyM at four more sites and evaluating its adoption, usability, and impact on clinical outcomes.