We describe the daily work activities of 13 Depression Clinical Specialists (DCSs) at 7 national sites who served as care managers in an effective multisite randomized trial of a disease management model for depression in primary care. DCSs carried portable random-reminder beepers for a total of 147 consecutive workdays and recorded 4,030 work activities. Patient care activity comprised the largest percentage of the workday, 49.4% (95% confidence interval [CI], 42.0 to 56.7%), followed by research-related activity, 18.3 % (95% CI, 14.7 to 21.9%), administrative work, 17.9% (95% CI, 12.2 to 23.7%), personal time, 9.4% (95% CI, 5.4 to 13.4%), and time in transit, 5.1% (95% CI, 2.8 to 7.4%). The DCSs delivered 19.2% (95% CI, 14.4 to 24.1%) of direct patient care by telephone. The DCSs spent a significant portion of the day alone 48.7% (95% CI, 43.3 to 54.1%), followed by time spent with patients, 37.5% (95% CI, 31.6 to 43.3%). Less than 10% (7.8%) (95% CI, 5.1 to 10.6%) of their time was spent with local study staff. Less than 4% of their time was spent with other health care providers. Our results demonstrate that the DCSs' time was primarily devoted to clinical care, a significant portion of which was delivered by telephone. They functioned independently, making efficient use of the limited amount of time that they interacted with other health care providers. This information will be helpful to those who may wish to implement this disease management strategy.