To review the literature on the subject of quality improvement principles and methods applied to pharmacy services and to describe a framework for current and future efforts in pharmacy services quality improvement and effective drug therapy management. The Academy of Managed Care Pharmacy produced the Catalog of Pharmacy Quality Indicators in 1997, followed by the Summary of National Pharmacy Quality Measures in February 1999. In April 2002, AMCP introduced Pharmacy's Framework for Drug Therapy Management in the 21st Century. The Framework documents include a self-assessment tool that details more than 250 specific "components" that describe tasks, behaviors, skills, functions, duties, and responsibilities that contribute to meeting customer expectations for effective drug therapy management. There are many opportunities for quality improvement in clinical, service, and cost outcomes related to drug therapy management. These may include patient safety; incidence of medical errors; adverse drug events; patient adherence to therapy; attainment of target goals of blood pressure, glucose, and lipid levels; risk reduction for adverse cardiac events and osteoporotic-related fractures; patient satisfaction; risk of hospitalization or mortality; and cost of care. Health care practitioners can measure improvements in health care quality in several ways including (a) a better patient outcome at the same cost, (b) the same patient outcome at lower cost, (c) a better patient outcome at lower cost, or (d) a significantly better patient outcome at moderately higher cost. Measurement makes effective management possible. A framework of component factors (e.g., tasks) is necessary to facilitate changes in the key processes and critical factors that will help individual practitioners and health care systems meet customer expectations in regard to drug therapy, thus improving these outcomes. Quality improvement in health care services in the United States will be made in incremental changes that rely on a structure-process-outcome model. The structure is provided by evidence created from controlled randomized trials and other studies of care and system outcomes that are based on the scientific method. The process portion is created by the application of evidence in the form of clinical practice guidelines, clinical practice models, and self-assessment tools such as Pharmacy's Framework for Drug Therapy Management. Incremental changes in structure and process will result in the desirable outcome of meeting customer needs for more effective drug therapy and disease management. Authors Richard N. Fry and Steven G. Avey are employed by the Foundation for Managed Care Pharmacy, a nonprofit charitable trust that serves as the educational and philanthropic arm of the Academy of Managed Care Pharmacy; author Frederic R. Curtiss performed the majority of work associated with this manuscript prior to becoming editor-in-chief of the Journal of Managed Care Pharmacy. This manuscript underwent blinded peer review and was subject to the same standards as every article published in JMCP.