For several decades both medical and social work practices have failed to consistently include measures to determine the effectiveness of their care and practices. This is especially true of care management practices. With the growth and aging of our population, this is of particular concern when many of our resources for older adults are channeled into services such as geriatric care management. This article describes a randomized controlled trial that tested the effectiveness of four levels of geriatric care management. Results from this study did not support the tacit knowledge of the clinicians in terms of the effectiveness of their practices. This article describes the study methods and results, and how evidence from this study impacted subsequent service provided by geriatric care managers.