Effective care coordination requires risk stratification, but little evidence has been collected about how it impacts clinicians. This care coordination pilot project created a unique opportunity to observe care coordination activities for 10,000 patients over 18 months, before and after risk stratification. Risk stratification feedback increased care coordination contacts with high-risk patients, without decreasing contacts with low-risk patients. The results of this study provide quantitative evidence of the importance of risk stratification in care coordination.