Cost-effectiveness evaluations play an important role in recommendations for use of pediatric vaccines that are set forth by the US Advisory Committee on Immunization Practices (ACIP). The fact that these evaluations are undertaken and accorded weight suggests that a critical value for designating pediatric vaccines as cost-effective (or not) must exist. For recommended pediatric vaccines, however, reported incremental cost-effectiveness ratios (ICERs) have varied greatly, and there does not appear to be an explicit threshold used by the ACIP to define how much is too much to pay for the prevention of communicable diseases in children. Further complicating this issue is the fact that conventional ICER thresholds-expressed in terms of cost per quality-adjusted life-year (QALY) gained-accord value only to length and quality of life and may not reflect our preferences as individuals or a society. For example, risk, an important attribute of many healthcare decisions, is ignored by the QALY model, as is the distribution of health benefits across different members of society. Are we indeed indifferent about risk and do we really believe that the value of disease prevention in children should be measured by the same “yardstick” as that for older adults? Accordingly, do we really believe that “a QALY is a QALY”? These issues, which are reviewed and discussed in this article, are more than just of theoretical interest; the answers impact how public health policy is determined, which impacts the lives and well-being of entire populations as well as the budgets of payers.