Quality in health care refers to a systems approach to evaluating and improving the health of the individuals served and is closely linked to quality improvement (QI) as an ongoing process of problem identification, intervention, evaluation, and further refinements in service delivery. QI strives for measureable improvements in services and health status of targeted patient groups. Significant variations in health care services have been well documented in various areas including stroke rehabilitation, brain injury outcomes, and the management of acute myocardial infarctions, hip fractures, colon cancer, diabetes, and depression, along with surgical procedures such as coronary artery bypass graft, hysterectomies, and spinal procedures. Risk-adjusted rehabilitation functional outcomes vary by insurance type, geographic region, and race/ethnicity. The variations in patient outcomes, high rates of medical errors, and heath care costs imply that changes in service delivery could lessen these disparities and improve the overall quality of care.