Initiatives to boost public trust of government often rely on better reporting of the efforts and accomplishments of government agencies. But if citizens disbelieve the performance reports of agencies, especially information about good performance, then these initiatives may be do little to enhance trust. We ask the following questions: Do citizens find performance information from government agencies to be credible, or do they trust more in independent sources? Do they believe some agencies more than others? And does credibility of the agency itself as a source depend on the level of performance that is being reported? To address these questions, we designed an experiment to test the credibility of a customer satisfaction index for two U.S. federal agencies, with random allocation of the specific agency (one politically less attractive, the other more so), the source of the index (the federal agency itself or an independent rating firm), as well as the level of performance reported in the index. Results from an online sample of nearly 600 U.S. adults show that credibility is lower for the politically less attractive agency and that citizens are especially doubtful about good performance reported by the government agency itself (as opposed to the independent rating firm). These results suggest that independent sources can boost credibility when reporting good news about government performance.