Although immigration remains a sensitive policy topic, over 24 percent of citizen children in the United States have at least one immigrant parent. These citizen children with immigrant parents are disproportionately uninsured even when they are eligible for Medicaid. In 2005, 15 percent of low-income citizen children in nonimmigrant families were uninsured. In contrast, 24 percent of low-income citizen children in immigrant families and 48 percent of noncitizen children remained uninsured (Ku 2007). While children in immigrant families are more likely to be uninsured than children in native families (Huang, Yu, and Ledsky 2006), national estimates can mask important enrollment disparities in states that are not traditional immigration gateways. Contributing to these state differences is the fact that states enjoy broad discretion in the administration of their individual Medicaid programs. This article examines which states successfully enroll their Medicaid-eligible, citizen children with immigrant parents. A state's experience with immigration can greatly facilitate the Medicaid enrollment experience for citizen children with immigrant parents, but relatively few states have a long history of immigration. In 1990, almost 75 percent of immigrants lived in six states (California, New York, Florida, Texas, New Jersey, and Illinois). These traditional gateway states have comparatively well-developed approaches for enrolling immigrant children in Medicaid, drawing on large, bilingual populations and well-established community organizations. However, more recent immigrants and their families have increasingly settled in states outside these traditional destinations. Between 1990 and 2005, the immigrant population doubled in the new destination states, defined as all states except the six traditional immigration gateways (CA, FL, IL, NJ, NY, and TX) (Frey 2006). Some of these new destination states have actively supported immigrants with English language classes and bilingual job markets, whereas other states have erected barriers by passing English-only laws and criminalizing immigration violations with local trespassing ordinances. Local regulations relating to immigration have no direct impact on a citizen child's Medicaid eligibility, but all these circumstances have a direct impact on the probability that immigrant parents will go to a local government office to enroll their child. Federal legislation encourages states to enroll Medicaid-eligible children. Specifically, the Children's Health Insurance Program Reauthorization Act (CHIPRA) includes performance bonuses for states that successfully increase enrollment of Medicaid-eligible children. The CHIPRA legislation allows for bonus payments to states that enroll more uninsured Medicaid-eligible children. To qualify for a bonus, states must first implement program features to facilitate enrollment. With the new program features in place, states can then receive an enhanced federal match if their Medicaid enrollment exceeds a baseline level set for their state (Centers for Medicare and Medicaid Services 2009). Furthermore, the 2014 Medicaid expansions scheduled under the Affordably Care Act (ACA) can be expected to disproportionately increase enrollment for children in native families as native parents will now have the incentive to enroll both themselves and their children in Medicaid. Children in immigrant families are not alone in remaining uninsured, with two-thirds of all uninsured children being eligible for Medicaid and CHIP (Cutler and Kenney 2007; Hudson 2009). Following the enactment of CHIP, all states increased the eligibility thresholds for children and efforts were made to simplify and improve enrollment and retention processes to reduce the number of eligible children who remain uninsured. Despite increased funding for outreach and enrollment efforts, Medicaid participation rates vary widely across states, ranging from 66 percent of eligible children enrolled in the Southern states to 80 percent of eligible children enrolled in the Northeast (Holahan, Dubay, and Kenney 2003). Similarly, maintaining coverage can be challenging, with up to 40 percent of Medicaid children in some states having a break in coverage (Fairbrother, Emerson, and Partridge 2007) or 50 percent in other states dropping out of Medicaid each year (Sommers 2007). Many state-specific factors likely contribute to these differences in participation. These hurdles can include in-person applications at multiple locations, lengthy forms, and extensive documentation requirements (Ross and Hill 2003). States have implemented multiple strategies to facilitate enrollment in Medicaid, including expanding coverage to parents, extending time between renewals, eliminating asset tests, and streamlining verification requirements (Kronebusch and Elbel 2004; Wolfe and Scrivner 2005; Sommers 2006; Summer and Mann 2006). Estimates of Medicaid participation for children with immigrant parents are limited to the largest states. In large states, children with immigrant parents are disproportionately uninsured, even when eligible for Medicaid (Acevedo-Garcia and Stone 2008; Yu, Huang, and Kogan 2008). However, data limitations have prevented these studies from examining Medicaid enrollment for children in most of the new destination states. Medicaid and CHIP eligibility for immigrant children varies widely across states. Both programs have always excluded undocumented immigrants, but the welfare reform (PRWORA) made immigrants who arrived after August 1996 ineligible for federally funded Medicaid until they reach 5 years of residency (Kaushal and Kaestner 2005). Multiple studies examine the “chilling effect” of PRWORA on insurance coverage for immigrant children and children with immigrant parents (Ku and Matani 2001; Kaushal and Kaestner 2005; Pati and Danagoulian 2008). After PRWORA, twenty-one states, including the six traditional gateway states, maintained eligibility for immigrant children in their Medicaid and CHIP programs, choosing to fund their benefits from local budgets until they met the residency requirement to receive the federal contribution (Ku 2009). Only in 2009, with the passage of the Children's Health Insurance Program Reauthorization Act was this exclusion of immigrant children removed, but the decision to cover noncitizen immigrant children remains optional based on the priorities of each individual state (Garner 2009). However, household surveys from the Census Bureau do not collect immigration status for noncitizens. Without information on whether a child is an undocumented alien, temporary resident, or permanent resident, it is not possible to identify Medicaid eligibility for noncitizens. Due to this limitation and the fact that 89 percent of children in immigrant families are U.S. citizens, this article only examines citizen children who meet state income eligibility criteria. This study will use the 2008, 2009, and 2010 American Community Survey (ACS) to examine public insurance take-up (Medicaid and the Children's Health Insurance Program or CHIP) for eligible citizen children in immigrant families. A state fixed-effects probit model estimates the probability of any insurance coverage based on the new ACS insurance questions introduced in 2008. The regression model tests which states have achieved comparable enrollment rates for citizen children in immigrant and nonimmigrant families. Policy simulations rank states to reveal which states are most successful at enrolling their citizen children with immigrant parents. Rather than finding traditional gateway states leveraging their immigration experience, this article finds gateway states among the most and least successful at enrolling their Medicaid-eligible children with immigrant parents.