This article presents a model that introduces a scientific 'gold' standard as a reputation protection mechanism operating alongside an agency's legal independence. It tries to gauge which of the two is less susceptible to political moves. The model suggests that the scientific 'gold' standard for agency decisions is less susceptible to political moves because of its important role as a legitimating device for both government ministers and regulators. Government ministers are able to address multiple audiences and even to respond to aggressive strategies by powerful interest groups by undermining one reputation protection mechanism (that is, an agency's independence) without weakening the other (that is, the scientific barrier for granting full-subsidy status to treatments that lack comparative therapeutic advantage). This implies that drug reimbursement mechanisms that provide a high quality of drug evaluation are designed to be effective.