In summary, the AHRQ QIs are a set of readily available programs that can be downloaded without charge from the AHRQ Web site. The methodology is completely open and accessible to all users. The QI software can be applied to hospital administrative data that is available within individual institutions or from state data organizations and hospital associations and can provide valuable insights into health care quality at extremely low cost. The QIs have been incorporated into numerous quality assessment reports, including hospital-specific reports, with the aim of improving health care quality at a reasonable cost. With enhancements currently underway, the QIs will be an even more valuable part of the toolkit to improve health care quality in the United States.