Background: More focus on patient-centeredness in care for patients with type 2 diabetes requests increasing attention to diabetes quality management processes on patient-centeredness by managers in primary care groups and outpatient clinics. Although patient-centered care is ultimately determined by the quality of interactions between patients and clinicians at the practice level, it should be facilitated at organizational level too. This nationwide study aimed to assess the state of diabetes quality management on patient-centeredness at organizational level and its possibilities to improve after a tailored intervention. Methods: This before-after study compares the quality management on patient-centeredness within Dutch diabetes care groups and outpatient clinics before and after a 1-year stepwise intervention. At baseline, managers of 51 diabetes primary care groups and 28 outpatient diabetes clinics completed a questionnaire about the organization’s quality management program. Patient-centeredness (0%-100%) was operationalized in six subdomains: facilitating self-management support, individualized care plan support, patients’ access to medical files, patient education policy, safeguarding patients’ interests, and formal patient involvement. The intervention consisted of feedback and benchmark and if requested a telephone call and/or a consultancy visit. After 1 year, the managers completed the questionnaire again. The 1-year changes were examined by dependent (non) parametric tests. Results: Care groups improved significantly on patient-centeredness (from 47.1% to 53.3%; P=0.002), and on its subdomains “access to medical files” (from 42.0% to 49.4%), and “safeguarding patients’ interests” (from 58.1% to 66.2%). Outpatient clinics, which scored higher at baseline (66.7%) than care groups, did not improve on patient-centeredness (65.6%: P=0.54) or its subdomains. “Formal patient involvement” remained low in both care groups (23.2%) and outpatient clinics (33.9%). Conclusion: After a simple intervention, care ...