Posted on October 10, 2018

Births to Legal and Illegal Immigrants in the U.S.

Steven A. Camarota, Karen Zeigler, and Jason Richwine, Center for Immigration Studies, October 9, 2018


This analysis looks at births to immigrants based on an analysis of the Census Bureau’s American Community Survey (ACS). It provides a good picture of births to immigrant mothers, including the mothers’ demographic characteristics.1 These characteristics allow us to estimate the likely number of births to illegal immigrants nationally, as well as births by state and by large metropolitan area.

National Picture

  • In 2014, one in five births (791,000) in the United States was to an immigrant mother (legal or illegal). Our best estimate is that legal immigrants accounted for 12.4 percent (494,000) of all births, and illegal immigrants accounted for 7.5 percent (297,000).
  • The 297,000 births per year to illegal immigrants is larger than the total number of births in any state other than California and Texas. It is also larger than the total number of births in 16 states plus the District of Columbia, combined.
  • The estimated 28,000 births to illegal immigrants in just the Los Angeles metro area is larger than the total number of births in 14 states and the District of Columbia.
  • Among the native-born, a large share of new mothers (42 percent) are either uninsured or on Medicaid. The rate is even higher among new mothers who are legal immigrants (47 percent) and higher still for new mothers who are in the United States illegally (67 percent). {snip}
  • {snip} Illegal immigrants account for 11 percent (198,000) of all publicly funded births, and legal immigrants are another 13 percent (231,000).
  • We estimate that the cost to taxpayers for births to immigrants (legal and illegal) is roughly $5.3 billion — $2.4 billion of which is for illegal immigrants.
  • Although immigration adds enormously to the number of births, it raises the nation’s overall birth rate by only 4 percent, partly because immigrant fertility is not that much higher than that of natives.


Possible Undercount of New Mothers. The National Center for Health Statistics (NCHS) records virtually all births in the United States. In the ACS, birth data comes from self-reported responses from women ages 15 to 50 who indicate whether they gave birth in the last year. Overall, the NCHS and ACS numbers line up well. The ACS shows 3.971 million new mothers in 2014, while the NCHS data shows 3.988 million births to U.S. residents — a 0.4 percent difference.3

However, the ACS and NCHS do not agree as closely when it comes to the number of births to immigrants specifically. Looking only at U.S. residents, the 2014 NCHS data shows 872,256 births to immigrants, while the ACS shows 790,582 births. The 81,674 difference is partly due to differing definitions. The ACS does not count those born aboard to American parents as immigrants. By contrast, the NCHS data records information about the mother’s country of birth only, not her citizenship. Therefore, the NCHS foreign-born number includes those born aboard to American parents. It is possible to calculate the number of births in the ACS data using the NCHS definition of the foreign-born. But the ACS still shows about 5 percent fewer immigrant births. This may mean that the undercount of immigrant births in the ACS is about 5 percent because immigrant mothers misreport that they are native-born. For the purposes of this analysis, we accept the figures in the ACS and report them without adjusting for undercount.4

Estimating the Illegal Population. Illegal immigrants are present in Census data, but they are never explicitly identified by the Bureau. To determine which respondents are most likely to be illegal aliens, CIS follows a methodology similar to those used by the Pew Research Center and the Center for Migration Studies.5 We start by eliminating immigrant respondents who are almost certainly not illegal aliens — for example, spouses of natural-born citizens; veterans; people who receive direct welfare payments (except Medicaid for women who gave birth within the past year and for residents of certain states); people who have government jobs; Cubans (because of special rules for that country); immigrants who arrived before 1980 (because the 1986 amnesty should have already covered them); people in certain occupations requiring licensing, screening, or a government background check (e.g., doctors, pharmacists, and law enforcement); and people likely to be on student visas.

The remaining candidates are weighted to replicate known characteristics of the illegal population (size, age, gender, region or country of origin, state of residence, and length of residence in the United States) as determined by the Department of Homeland Security (DHS).6 The resulting illegal population, which consists of a weighted set of ACS respondents, can then be used to infer characteristics not published by DHS, such as births and Medicaid use by illegal aliens.

Of course, all profiles of the illegal immigrant population carry significant uncertainty, and the share of births to illegal immigrant mothers across the United States are no exception. Since our estimates become less precise in smaller geographic areas, we limit the data for specific metro areas to the 50 largest by total population.

Births Paid for by Taxpayers. The public cost of delivery or post-partum care is paid for by Medicaid under the “pregnancy care” provision administered by the states. Medicaid will pay for a delivery in almost all cases if the mother is uninsured or has a low income, though some mothers without insurance may not even realize the program has paid health care providers. Illegal immigrants and most new legal immigrants are ineligible for Medicaid, but the program will still cover the cost of delivery and post-partum care for these mothers for at least a few months. Funding for Medicaid comes from both the federal government and the states.

{snip} In the ACS, 99 percent of the children under one year of age whose mothers are on Medicaid are also insured by the program.7 Of new immigrant mothers who report they are uninsured at the time of the survey, 84 percent of their newborns are covered by Medicaid.

By examining new mothers in the ACS who are uninsured or on Medicaid, we are looking at women whose delivery was, in almost all cases, paid for by taxpayers. In fact, the share of all new mothers (immigrant and native) who are on Medicaid or uninsured (44 percent) in the ACS is close to the 43 percent of all births paid for by Medicaid reported by the NCHS.8

Estimating the costs of publicly financed births is difficult. The amount that Medicaid spends per birth on mother and child is not something the federal government and states report. {snip} Adjusting to 2014 dollars, the middle year of the ACS data in this report, would increase the amount to $13,596. We assign this cost to new mothers on Medicaid. As discussed above, 84 percent of uninsured new mothers have a child less than one year of age who is covered by Medicaid. We therefore assume that 84 percent of births to uninsured mothers were covered by Medicaid. We implement this by assigning only 84 percent of the cost of publicly funded births to new mothers who report they are uninsured at the time of the survey. This is a conservative estimate as it is likely that a larger share of these births were in fact publicly funded since only a small share of births are actually “self-pay”.9 Using this approach produces an estimate of $5.3 billion in taxpayer money going to fund births to immigrants in 2014, $2.35 billion of which is for illegal immigrant births. {snip}

[Editor’s Note: The original story contains tables, charts, footnotes, and an Excel spreadsheet.]