On November 3, 2015, the Center for Migration Studies of New York (CMS) published a paper in its Journal on Migration and Human Security with new estimates of the US “eligible-to-naturalize” population. The spreadsheet available for download below provides the estimated population eligible to naturalize, by country of origin and state of residence.
Estimated population potentially eligible to naturalize, by country of origin and state of residence: 2013
CMS derived its estimates from data collected in the US Census Bureau’s American Community Survey (ACS) in 2013. The estimation procedure relied on the ACS questions on country of birth, citizenship status, and year of immigration. All of the estimation was done at the micro data level. CMS compiled data for non-US citizens who entered before mid-2008, removed those that it had previously identified as undocumented residents, and made adjustments that took into account specific residency requirements of refugees, spouses of US citizens, and active-duty military.
As described in its journal article, the CMS estimates were derived from data collected in a very large – 1 in 100 – national survey. As such, they are subject to sampling variability as well as non-sampling errors, such as possible errors in the assignment of legal status of noncitizens. The estimates for smaller geographic areas should be used with caution. Because small numbers are relatively less reliable, numbers that round to fewer than 500 are not shown. As a result, items might not sum to the totals shown.
 Warren, Robert and Donald Kerwin. 2015. “The US Eligible-to-Naturalize Population: Detailed Social and Economic Characteristics.” Journal on Migration and Human Security 3(4): 306-29. https://doi.org/10.1177/233150241500300401.
 The ACS is an annual statistical survey conducted by the Census Bureau. It covers approximately one percent of the total US population. The survey gathers information previously obtained in the decennial census long form. The public-use data from the survey provides detailed social and economic data for all states, as well as all cities, counties, metropolitan areas, and population groups of 100,000 people or more.
 Most of those in the 2013 ACS who entered after mid-2008 would not meet the five-year residency requirements to naturalize. See Appendix A of the journal article for a detailed description of the methodology.