Medication reconciliation (MR) is the process of identifying the most accurate list of all medications a patient is taking, including the name, dosage, frequency, and route of each medication, and using this list to provide correct medications for the patient anywhere within the health care system. Evidence indicates that medication discrepancies can affect patient outcomes, and MR is intended to identify and resolve these discrepancies. Adverse drug events (ADE) associated with medication discrepancies can prolong hospital stays and, in the post-discharge period, may lead to emergency room visits, hospital readmissions, and utilization of other healthcare resources. This case study is designed primarily to enhance understanding of fundamental concepts, principles, and facts of MR in a hospital setting. It is run as directed case and can be completed in 45 minutes. The case was designed for interns in an internal medicine program, but is also transferable to third and fourth year medical students as well as pharmacy, nursing, NP and PA students.