The United States Pharmacopeia (USP), a private non-profit organization, facilitates the anonymous reporting and tracking of medication errors within the hospital setting via the Medication Errors Reporting Program and the MEDMARX Program. USP shares information with the National Coordinating Council for Medication Error Reporting and Prevention to increase reporting, understanding, and prevention regarding medication use. MEDMARX collects and reports at which stage (prescribing, transcribing/documenting, dispensing, administering, monitoring) in the medication use process an error occurs. Over a million medication errors are documented through MEDMARX. The four most common errors, include missed dose(s), wrong dose/quantity, prescribing errors, and unauthorized drug errors. In the last 5 years, insulin, heparin, albuterol, morphine, potassium chloride, and warfarin are consistently in the top 10 agents associated with medications errors and involve both harmful and nonharmful medication errors. This high number of reports provides valuable information-allowing for identification of areas needing improvement and the development of actions to reduce recurring trends-to ultimately improve patient safety.