Carle's Medicare Coordinated Care Demonstration care/disease management interventional components, based on the chronic care model, are described for elderly patients in 13 counties in Illinois. Patients enrolled in the program are diagnosed with chronic obstructive pulmonary disease, coronary artery disease, diabetes, atrial fibrillation, or congestive heart failure. Primary care teams are made up of a primary care physician, an advanced practice nurse, a nurse case manager, and a case assistant. The patient/family is the cornerstone of the intervention, which is evaluated using a prospective, longitudinal randomized treatment-control design.