BACKGROUND: The Chronic Care Model (CCM) is a widely used conceptual model for improving chronic illness care, but there is limited evidence to support the validity of this model. Seventeen clinics in a single medical group used the CCM in a diabetes improvement initiative, and the study tested which CCM components at the clinic level were associated with improved glycohemoglobin (A1C) and low-density (LDL) outcomes for patients with diabetes. DESIGN: Three leaders from each of 17 clinics completed a survey in 2002 that assessed the presence of CCM components in their clinics. Clinic scores from this survey were correlated with change in clinic-level measures of the quality of care for their diabetes patients (A1C and LDL outcomes) during the preceding year. RESULTS: Delivery system design (DSD) scores were positively correlated with improvements in A1C and lipid test rates and levels at these clinics (r = 0.49-0.57, p < .05). Self-management support and clinical information systems demonstrated associations that may have substantive significance but did not reach p < 05. CONCLUSIONS: These data suggest that delivery system design is associated with improved A1C and LDL outcomes for people with diabetes. Additional studies are necessary to determine the association of other CCM components with improved outcomes.