OBJECTIVE - Diabetes care can be limited by clinical inertia-failure of the provider to intensify therapy when glucose levels are high. Although disease management programs have been proposed as a means to improve diabetes care, there are few studies examining their effectiveness in patient populations that have traditionally been underserved. We examined the impact of our management program in the Grady Diabetes Unit, which provides care primarily to urban African-American patients with type 2 diabetes. RESEARCH DESIGN AND METHODS - We assessed glycemic outcomes in patients with type 2 diabetes who had an intake evaluation, between 1992 and 1996 and who were identified on the basis of compliance with keeping the recommended number of return visits. Fur 698 patients, we analyzed changes in HbA(1c) values between baseline and follow-up visits at 6 and 12 months, and the proportion of patients achieving a target value of less than or equal to 7.0% at 12 months. Since a greater emphasis on therapeutic intensification began in 1995, we also compared HbA(1c) values and clinical management in 1995-1996 with that of 1992-1994. RESULTS - HbA(1c) averaged 9.3% on presentation. After 12 months of care,HbA(1c) values averaged 8.2, 8.4, 8.5, 7.7, and 7.3% for the 1992-1996 cohorts, respectively, and were significantly lower compared with values on presentation (P < 0.0025), the average fall in HbA(1c) was 1.4%. The percentage of patients achieving a target HbA(1c) less than or equal to 7.0%, improved progressively from 1993 to 1996, with 57% of the patients attaining this goal in 1996. Mean HbA(1c) after 12 months was 7.6% in 1995-1996, significantly improved over the level of 8.4% in 1992-1994 (P < 0.0001). HbA(1c) levers after 12 months of care were lower in 1995-1996 versus 1992-1994, whether patients were managed with diet alone, oral agents, or insulin (P < 0.02). Improved HbA(1c) in 1995-1996 versus 1992-1994 was associated with increased use of pharmacologic therapy. CONCLUSIONS - Structured programs tan improve glycemic control in urban African-Americans with diabetes. Self-examination of performance focused on on overcoming clinical inertia is essential to progressive upgrading of care.