Medication errors are likely the most common patient safety threat in ambulatory care, and this survey of primary care patients revealed many issues that are putting patients at risk for adverse drug events. Patients assumed that their primary care doctor was aware of all their medications, including those prescribed by other physicians, despite evidence documenting poor information sharing between community physicians. Although prior studies show that pharmacist counseling may reduce medication error rates in outpatients, only a minority of patients receiving new prescriptions reported receiving counseling (from a physician or pharmacist) regarding potential adverse effects. The discordance between patient assumptions and physician knowledge about medication regimens points to a need for greater patient engagement in medication reconciliation efforts.