Definitions of immigrant populations, as well as the criteria that determine these definitions, differ from one country to another. However, according to the Organisation for Economic Co-operation and Development (OECD), the most commonly used definitions are based upon country of birth and nationality (OECD 2013). Using country of birth criteria, immigrant populations are defined as those who live in a country (known as host country) different from that in which they were born. Where nationality criteria are used, immigrant populations are defined as those holding a nationality different from the host country. Under this scenario, a person may be considered an immigrant even if he or she was born in the host country. The criteria used can also reflect the host country’s view of how citizenship may be acquired (OECD 2013). For instance, country of birth criteria reflects jus soli—the right of the soil by which citizenship is automatically linked to place of birth, while nationality reflects jus sanguinis—the right of blood, wherein citizenship is derived from the nationality of the parents. Generally, countries have self-determined paths from “immigrant” to “national” status. Variations exist and depend upon or are influenced by each country’s rules governing how citizenship may be acquired by non-nationals, however defined. Foreign-born persons may acquire citizenship through a naturalization process, while those who do not do so remain non–citizens.

Countries also prescribe the manner in which immigrants may reside legally in the host country. For instance, in the USA, those who follow established rules for migration are known as documented immigrants, while those who do so without legal authorization are considered undocumented immigrants.

According to the US Census Bureau’s American Community Survey (ACS), in the USA, the term foreign born refers to persons who are not US citizens at birth, including naturalized citizens, legal permanent residents, and other classes of migrants such as the temporary (e.g., students), humanitarian (e.g., refugees), as well as undocumented migrants (US Census Bureau: American Community Survey Report 2012b). Native born refers to those born in the US, Puerto Rico, or the US Island Area, or those born abroad to at least one parent who is a US citizen (ACS 2012b). In 2012, the total US population was 313,914 million (Census Bureau 2012a, b; OECD 2013a). According to the 2010 ACS, about 13 % of US population (40 million) is foreign born. Department of Homeland Security estimates indicate that approximately 11.5 million are undocumented (Hoefer et al. 2011). OECD data reflect a growing trend in immigrant populations , with higher immigrant numbers for countries such as Canada, Australia, Israel, and New Zealand that range from 20 to 40 % of their total populations (OECD 2013b).

In sum, immigrant populations include foreign-born persons or persons who still hold a nationality other than that of the host country; they may be documented or undocumented , and their numbers continue to increase (OECD 2013b).

Immigrant populations often exhibit demographic and socioeconomic differences when compared to their native-born counterparts. Status differences within immigrant populations exist, for instance, by race, country of origin, length of stay in the host country (recent or earlier immigrants), and whether they are documented or undocumented aliens (OECD 2013). The vast majority (about 2/3rds) of immigrants have come to the USA since 1990. Generally, compared to native-born populations, immigrants are more likely to be at a disadvantage socioeconomically: with lower levels of education, higher levels of labor force participation, lower income, and a higher likelihood of living in poverty (ACS 2010).

The growth in both the aging and immigrant segments of the US population give credence to an increased interest in LGBT elders. As both segments grow as a percentage of the overall population, we can expect a parallel increase in the LGBT population. For those involved, the key issues that affect immigrant populations and aging populations join those affecting LGBT populations. Consequently, immigrant LGBT elders are likely to face multiple jeopardy owing to disadvantages due to age, immigrant status, and sexual orientation.

Elders, persons aged 65 and over, comprise approximately 13 % of the US population (US Census Bureau 2012). In the absence of precise data about the number of foreign-born LGBT persons in the USA, the Williams Institute on Sexual Orientation and Gender Identity Law and Public Policy at UCLA School of Law (Williams Institute) conducted an analysis of data from multiple sources including the Pew Research Hispanic Center, Gallup Daily Tracking Survey data, and the US Census Bureau’s 2011 American Community Survey. As reported by Gates (2013), this analysis estimates that there are approximately 804,000 foreign-born LGBT in the USA, of which about 70 % (637,000) are documented and 30 % (267,000) are undocumented. Of that number, it is estimated that persons 55 and over make up about 22 % of immigrants who self-identify as LGBT, while among the undocumented, the number is about 4 % (Gates 2013). Because many LGBT individuals are reluctant to identify as such, these estimates may be undercounts. LGBT elder immigrants (both self-identified and otherwise) can be broadly divided into two groups—recently arrived immigrants and earlier cohorts of immigrants who have aged in place within their host country. Together, they make up a significant segment of the US population. This fact, coupled with the fact that there are currently a large number of younger LGBT immigrants who will likely age in place over time, makes a focus on this group pertinent and timely.