OBJECTIVE To characterize patient and clinician perceived barriers and facilitators to using electronic patient-generated data (PGD) in safety-net systems. METHODS We conducted 43 semi-structured interviews (18 clinicians and 25 patients) and observed 15 patient-clinician interactions. Clinical observations were conducted in an integrated urban safety-net system. Patients who spoke English, Spanish, or Cantonese were recruited from this system. Pharmacists, nurses, and clinicians treating chronic diseases were sampled from multiple California safety-net systems. Interview guides were developed based on the Consolidated Framework for Implementation Research (CFIR) and the Behavior Change Wheel (BCW). We conducted thematic analysis through a combination of inductive and deductive coding. RESULTS Themes most frequently identified by both clinicians and patients as impacting electronic PGD use were capability-related (knowledge about collecting and using PGD), motivation-related (preference for data sharing; attitude toward digital tools and learning how to use them; the importance of measuring the outcome for health; privacy; and patient-clinician relationship), and opportunity-related (social support). Non-English speakers expressed concerns about inconveniencing others. Clinicians also identified additional opportunity-related themes (resource availability; implementation process; external incentives). CONCLUSIONS Despite the growth in electronic PGD and its potential to improve chronic disease care and outcomes, implementation in safety-net systems would benefit from consideration of capability, motivation, and opportunity-related barriers. CONCLUSIONS PGD is an increasingly vital part of clinical care. If implementation is pursued without concurrently addressing factors at the patient, clinician, health system, and policy levels, barriers to adoption will persist, especially in under-resourced settings.