This article reviews recent survey-based research on citizens’ trust in government, focusing particularly on the United States. It addresses the long-term decline in trust and potential causes for this decline, with an emphasis on the effects of partisanship, polarization, performance, process, and media priming. While dispositions can anchor trust levels, the dominant research findings show that the sources of variation and change in trust are political, if multifaceted, in nature. We discuss new versions of standard measures, call for a renewed look at the distinction between trust in authorities and trust in the regime, review ongoing work on how and why trust matters, and recommend broadening the foci of mistrust to include antiestablishment sentiments and attacks on electoral integrity. How trust intervenes between perceptions of political processes and compliance with authoritative commands is a critical domain for additional research. We conclude with a caveat against confidence that the decline in trust can be quickly or easily reversed.