Transplant centers may "game" the severity of listed patients to increase their patients' likelihood of receiving transplantable organs. Recent lawsuits allege gaming at some centers, and listing policies were modified in 1999 to clarify listing criteria. We tested for gaming and its relationship to heart transplant center competition. We found that increased competition resulted in more patients listed in the most severe illness category (p < .01), consistent with the gaming hypothesis. Gaming was mitigated after the 1999 policy change (p > .05), which suggests that the new rules were effective. Continued monitoring is warranted, given prior gaming and recent accusations.