Importance Federal policy changes in 2002 and 2009 led some states to expand public health insurance coverage to non-US-born children and pregnant women who are lawful permanent residents during their first 5 years of residency in the United States. In other states, there were concerns that insurance expansion could attract immigrants to relocate to gain free health insurance coverage. Objective To examine whether expansion of public health insurance to non-US-born, lawful permanent resident children and pregnant women during their first 5 years of residency is associated with increased interstate migration among these groups. Design, Setting, and Participants This difference-in-differences analysis included data on 208 060 immigrants from the American Community Survey from 2000 through 2016, with analysis including all 50 states and the District of Columbia. The study sample included 2 treatment groups that became eligible under the expanded coverage: lawful permanent resident adults with at least 1 non-US-born child younger than 18 years (n = 36 438) and lawful permanent resident women of reproductive age (n = 87 418). Control groups that remained ineligible under the expanded coverage included lawful permanent resident adults without non-US-born children (n = 171 622), lawful permanent resident single men (n = 56 142), and lawful permanent resident postreproductive women (n = 15 129). A difference-in-differences design compared migration rates between eligible and ineligible immigrant groups before and after insurance coverage expansions. Data analysis was performed from November 3, 2018, to May 31, 2019. Exposures Public health insurance coverage for immigrant women and children who were lawful permanent residents within 5 years of residency. Main Outcomes and Measures Migration to a health expansion state from any other state and from a neighboring state. Results Of 208 060 immigrants (47% women in the weighted sample; mean [SD] age, 32.97 [12.94] years; 63% Hispanic), the mean (SD) annual move rate across the entire sample was 3% (17%). Expansion of public health insurance to non-US-born children or pregnant women within their first 5 years of residency was not associated with interstate movement for health care benefits. Coverage expansion for non-US-born children of lawful permanent residents was not associated with a change in the rate of in-migration higher than 1.78 percentage points or lower than -1.28 percentage points. The corresponding estimate for coverage expansion of lawful permanent resident pregnant women was a change higher than 1.38 percentage points and lower than -1.20 percentage points. Conclusions and Relevance The results suggest that states considering expanding health care benefits coverage to recently arrived immigrant children and pregnant women may be unlikely to experience in-migration of these persons from other states, which has important implications for understanding short- and long-term program costs.

中文翻译：

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扩大移民儿童的公共健康保险和低收入移民的州际移民

重要性 2002 年和 2009 年联邦政策的变化导致一些州将公共健康保险的覆盖范围扩大到非美国出生的儿童和在美国居住头 5 年期间成为合法永久居民的孕妇。在其他州，人们担心保险扩张可能会吸引移民搬迁以获得免费医疗保险。目的 研究将公共医疗保险范围扩大到非美国出生的合法永久居民儿童和居住前 5 年的孕妇是否与这些群体的州际移民增加有关。设计、设置和参与者 这项双重差分分析包含 2000 年至 2016 年美国社区调查中 208 060 名移民的数据，分析范围包括所有 50 个州和哥伦比亚特区。研究样本包括 2 个符合扩大覆盖范围资格的治疗组：至少有 1 个 18 岁以下非美国出生子女的合法永久居民成年人 (n = 36 438) 和育龄合法永久居民女性 (n = 87 418）。扩大覆盖范围后仍不符合资格的对照组包括没有非美国出生子女的合法永久居民成年人（n = 171 622）、合法永久居民单身男性（n = 56 142）和合法永久居民生育后女性（n = 15） 129）。双重差分设计比较了保险覆盖范围扩大之前和之后合格和不合格移民群体之间的迁移率。数据分析于2018年11月3日至2019年5月31日期间进行。暴露了居住5年内成为合法永久居民的移民妇女和儿童的公共健康保险覆盖范围。主要成果和措施 从任何其他州和邻近州迁移到健康扩张州。结果 在 208 060 名移民中（加权样本中 47% 为女性；平均 [SD] 年龄为 32.97 [12.94] 岁；63% 为西班牙裔），整个样本的平均 (SD) 年迁移率为 3% (17%) 。将公共健康保险范围扩大到非美国出生的儿童或怀孕妇女在居住的前 5 年内与跨州转移医疗保健福利无关。合法永久居民的非美国出生子女的覆盖范围扩大与移民流入率高于 1.78 个百分点或低于 -1.28 个百分点的变化无关。合法永久居民孕妇覆盖范围扩大的相应估计变化高于 1.38 个百分点，低于 -1.20 个百分点。结论和相关性 结果表明，考虑将医疗保健福利覆盖范围扩大到最近抵达的移民儿童和孕妇的州可能不太可能经历这些人从其他州的移民，这对于理解短期和长期计划具有重要意义成本。