OBJECTIVES: This study aims to evaluate medication adherence, utilization and costs associated with American Pharmacist Association's (AphA) Diabetes Care Project. METHODS: Patients with diabetes were assigned to an intervention or control cohort based on enrollment in APhA's Diabetes Care Project. Individual patients were included if they had at least two claims for diabetes medications and were continuously enrolled from April 1, 2002 to March 31, 2004. Retrospective pre-post cohort design, descriptive and multivariate modeling analyses were conducted to compare medication utilization between the two cohorts. RESULTS: A total of 118 patients (37 in the intervention and 81 in the comparison) were identified. There were no significant differences between the two cohorts in medication possession ratio (MPR), pharmacy costs, and the number of prescriptions of diabetes drugs, ACE inhibitors, and needles at baseline. During the 12-month post period, patients in the intervention were more likely to have a prescription for test strips (OR=144.9, p<0.0001) and needles (OR=11.7, p<0.0001). Compared to the baseline period, patients with pharmacist intervention had significantly more prescriptions for test strips (0.68 vs. 5.32), diabetes medications (6.24 vs. 11.41), needles (1.27 vs. 4.24) and ACE inhibitors (1.68 vs. 3.03), a higher MPR with diabetes drugs (0.67 vs. 0.96) and higher pharmacy costs ($689.9 vs. $1617.8), whereas patients in the comparison had no significant differences. CONCLUSIONS: APhA Diabetes Care Project significantly increased patients adherence to therapy and utilization for test strips, needles, diabetes medications and ACE inhibitors. The increased adherence to therapy may offer both clinical and cost benefits to patients. (Acknowledgments: American Pharmacists Association; The Manitowoc Health Care Coalition; Don F. Jabas Associates.)