NBER WORKING PAPER SERIES COVERING UNDOCUMENTED IMMIGRANTS: THE EFFECTS OF A LARGE-SCALE PRENATAL CARE INTERVENTION

Undocumented immigrants are ineligible for public insurance coverage for prenatal care in most states, despite their children representing a large fraction of births and having U.S. citizenship. In this paper, we examine a policy that expanded Medicaid pregnancy coverage to undocumented immigrants. Using a novel dataset that links California birth records to Census surveys, we identify siblings born to immigrant mothers before and after the policy. Implementing a mothers' fixed effects design, we find that the policy increased coverage for and use of prenatal care among pregnant immigrant women, and increased average gestation length and birth weight among their children. Sarah Miller Ross School of Business University of Michigan 701 Tappan Street Ann Arbor, MI 48109 and NBER mille@umich.edu Laura Wherry Wagner Graduate School of Public Service New York University 295 Lafayette Street New York, NY 10012 and NBER laura.wherry@nyu.edu There are nearly 11 million immigrants without legal status in the U.S. (Krogstad et al., 2018), and it is estimated that one out of every 13 births in the country is to an undocumented immigrant mother (Camarota et al., 2018). Undocumented immigrants are economically worse off and are less likely to have health insurance than the general U.S. population (Goldman et al., 2005; Borjas, 2017). They also face restricted access to public benefits. The Medicaid program covers the expense of labor and delivery for these women, but in most states undocumented immigrant women do not qualify for routine prenatal care during pregnancy. Available evidence indicates that undocumented immigrant women are less likely to use adequate prenatal care and experience more complications of labor and delivery than other women (Reed et al., 2005; Korinek and Smith, 2011). 1 By removing financial barriers to care, expanding public insurance for prenatal care to this population could increase access to health services and improve the health of these mothers and their children, who are U.S. citizens by birthright. In this paper, we examine one of the first expansions of prenatal coverage to undocumented immigrants: a landmark policy change in California, the state with the largest population of undocumented immigrants in the U.S. (Pew Research Center, 2016). In 1988, California extended eligibility for its Medicaid program, Medi-Cal, to undocumented pregnant immigrants who previously did not qualify for coverage due to their legal status. We estimate that nearly two-thirds of undocumented immigrant women of reproductive age gained Medi-Cal eligibility as a result. By 1991, 45 percent of Medi-Cal funded births in the state were to undocumented immigrant women, and one-sixth of all births in the state were Medi-Cal funded births to this group (Norton et al., 1996). 2 Representing approximately 100,000 births, the number of infants to undocumented immigrants with Medi-Cal coverage in 1991 exceeds the total number of births in any one of 41 different U.S. states in 2019 (Martin et al., 2021). While expanded public insurance has been a primary policy lever to improve infant health in the U.S., changes to cover prenatal care for women who are undocumented immigrants have been slower to be adopted. Congress enacted a series of federal statutes starting in the late 1980s that required states to expand Medicaid eligibility for pregnant women and infants (Howell, 2001). However, these expansions were limited to legal immigrants. Only more recently has federal policy addressed the 1There are few studies documenting prenatal care utilization and birth outcomes of immigrant mothers in the U.S. by legal status, likely due to the limited availability of data with detailed immigration information. The evidence cited here is from smaller-scale studies of immigrants in Colorado (Reed et al., 2005) and Utah (Korinek and Smith, 2011). 2We are including newly legalized immigrants under the Immigration Reform and Control Act (IRCA) in the "undocumented" category in our discussion here since this group also gained eligibility under the October 1988 expansion. Please see further discussion in Section 1.