In 2006 Congress passed, and the Centers for Medicare and Medicaid Services (CMS) rapidly issued, regulations requiring states to obtain proof of citizenship from citizens who had applied for Medicaid. This policy was framed as reducing fraud by illegal aliens to preserve benefits for citizens. In fact, evidence indicates there was no significant problem of fraud by immigrants, and the major effect of the policy was to reduce coverage of eligible citizens. This article addresses the reasons why Congress developed this policy and why CMS acted with uncharacteristic haste to implement these counterproductive policies. We note the importance of the policy's symbolic framing—that is, as establishing sanctions against illegal immigration—in congressional passage during a period of rising nativism in Congress and the nation. The regulatory actions reflected the ideological preferences of political appointees and an increasingly adversarial relationship between CMS and state agencies during this period. These haphazard regulatory actions made the policies more convoluted and likely led more eligible citizens to lose coverage. In 2009, Congress amended the law to modify implementation. These issues have continued to persist in the recent debate on national health care reform.