Since 2006, the Joint Commission has required all hospitals to have a process in place for medication reconciliation (MR). Although it has been shown that MR decreases medical errors, achieving compliance has proven difficult for many health care institutions. This article describes a housestaff-championed intervention of a "hard stop" for on-admission MR orders that led to a statistically significant increase in compliance that was sustained at 6 months after intervention. Academic medical centers, which comprise large numbers of housestaff, can improve compliance with on-admission MR by engaging housestaff in the development of solutions and in communication to their peers, leading to sustained results.