Context: Type 2 diabetes mellitus (T2DM) affects over 31 million Americans, including socially vulnerable, low-income, and minority populations who often experience worse diabetes-related outcomes. Understanding and acting on the patient’s perceived treatment burden may be one avenue for improving outcomes, but in our data to-date, there is not a clear association between treatment burden and diabetes control. Exploring patient experience by treatment burden and by HgbA1c may illuminate this complex relationship. Objective: To understand how the patient’s experience of care and of self-management is associated with perceived treatment burden and with HgbA1c. Study Design: Mixed methods study consisting of 1. Cross-sectional surveys measuring patient experience of treatment burden, demographics, and open-ended questions to assess experience with clinical care and self-management; and 2. electronic health record data. We use qualitative content analysis, and then repeat this analysis looking for convergence and divergence within each of 4 strata: 1. High treatment burden, high HgbA1c; 2. High treatment burden, low HgbA1c; 3. Low treatment burden, high HgbA1c; and 4. Low treatment burden, low HgbA1c. Setting: Six urban safety-net primary care clinics. Population Studied: 195 adults with T2DM and at least one additional chronic condition. Outcome measures: HgbA1c, patient experience of treatment burden (measured by the validated Patient Experience with Treatment and Self-management questionnaire), demographics; content analysis of open-ended questions that ask which clinic team member and resource are most useful and why, and which chronic condition is most burdensome and why. Results: Findings will include: 1) associations between perceived treatment burden and HgbA1c, and 2) patient experience of self-management of chronic conditions stratified into 4 groups by treatment burden and HgbA1c. We anticipate results will identify how the qualitative experience of care and of chronic disease self-management differs by perceived treatment burden and diabetes control. Conclusions: We anticipate sharing insights into a complex relationship between perceived treatment burden and diabetes control. This understanding will inform recruitment targets and intervention development aimed at decreasing specific aspects of treatment burden through an intervention to individualize and optimize care delivery for socially vulnerable patients with T2DM.