People who pay for health care aim to maximize value in allocating resources between and within patient groups. With limited health care budgets, new high value innovations will replace, not supplement, lower value interventions. Every society and its health care system must consider the issue of value and be aware that the values of payer, provider, clinician, and patient will always be different. Knowledge, while necessary, is never sufficient when commissioning health care. At times, decision maker's subjective values may outweigh objective evidence.