OBJECTIVE: Before cost-effectiveness analysis (CEA) can fulfill its promise as a tool to guide health care allocation decisions, the method of incorporating societal values into CEA may need to be improved. DESIGN: The study design was a declarative exposition of potential fallacies in the theoretical underpinnings of CEA. Two values held by many people-preferences for giving priority to severely ill patients and preferences to avoid discrimination against people who have limited treatment potential because of disability or chronic illness-that are not currently incorporated into CEA are discussed. CONCLUSIONS: Traditional CEA, through the measurement of quality-adjusted life years (QALYs), is constrained because of a "QALY trap." If, for example, saving the life of a person with paraplegia is equally valuable as saving the life of a person without paraplegia, then current QALY methods force us to conclude that curing paraplegia brings no benefit. Basing cost-effectiveness measurement on societal values rather than QALYs may allow us to better capture public rationing preferences, thereby escaping the QALY trap. CEA can accommodate a wider range of such societal values about fairness in its measurements by amending its methodology.