There is some evidence to demonstrate how a medication reconciliation process is effective at preventing adverse drug events. Few studies have been published demonstrating how to do the process effectively or outlining the costs associated with design and implementation of programs. Nonetheless, an effective medication reconciliation process across care settings—where medications a patient is taking are compared to what is being ordered—is believed to reduce errors. Comparing what is being taken in one setting with what is being prescribed in another will avoid errors of omission, drug-drug interactions, drug-disease interactions, and other discrepancies. Medication reconciliation is a major component of safe patient care in any environment.