Amid record encounters of migrants at the U.S.-Mexico border in fiscal years (FY) 2021 and 2022 and wide use of humanitarian parole to allow entry of migrants arriving without visas, the size of the unauthorized immigrant population has reached its highest level yet. The Migration Policy Institute (MPI) estimates that approximately 13.7 million unauthorized immigrants lived in the United States as of mid-2023, up from 12.8 million the year prior. MPI revised upwards its estimates for 2022 and prior years, using an updated methodology that permits better addressing the Census Bureau’s undercount of new immigrants.
Box 1. Measuring and Defining the Unauthorized Immigrant Population
These estimates derive from an updated Migration Policy Institute (MPI) methodology developed in collaboration with a demographer at The Pennsylvania State University that uses administrative data and data from the U.S. Census Bureau’s American Community Survey (ACS) to estimate the size of the unauthorized immigrant population overall, and for top countries and regions of birth. The methodology subtracts the number of legal immigrants of all categories, counted in administrative data, from the total count of the foreign born in the ACS, to estimate the number of unauthorized immigrants. The methodology also adjusts for the fact that the ACS has historically undercounted recently arrived immigrants.
MPI’s definition of the unauthorized immigrant population includes those who entered the country without authorization and visa overstayers, as well as individuals who hold a liminal (or “twilight”) status such as Deferred Action for Childhood Arrivals (DACA), humanitarian parole, or Temporary Protected Status (TPS), as well as those with a pending asylum application.
For a fuller description of MPI’s methodology, see Box 2.
Increase in the Unauthorized Population
Between 2019 and 2023, the unauthorized immigrant population grew by 3 million, or an average of 6 percent per year (see Figure 1). The nation had not seen yearly increases this large since the early 2000s.
This growth is partially explained by increased irregular arrivals at the U.S.-Mexico border, with a rising mix of nationalities from across the Western Hemisphere from countries such as Venezuela, Colombia, Cuba, Ecuador, and Nicaragua, as well as hundreds of thousands of people who entered with humanitarian parole from Ukraine, Mexico, Haiti, and other countries. And it also stems from sizable numbers of Europeans and others who overstayed their nonimmigrant visa.
Figure 1. Estimates of the Size of the U.S. Unauthorized Immigrant Population, 2010–23
Notes: Migration Policy Institute (MPI) estimates of the U.S. unauthorized immigrant population, developed in collaboration with Jennifer Van Hook from The Pennsylvania State University, Population Research Institute, are achieved by subtracting the number of legal immigrants (naturalized citizens, lawful permanent residents, and individuals on long-term nonimmigrant visas) from the total of all foreign-born individuals from major sending countries and regions represented in data from the U.S. Census Bureau’s American Community Survey. The number of legal immigrants is estimated by adding up all legal admissions from each country and region in every year—using U.S. Department of Homeland Security (DHS) administrative data—and then reducing this number to account for deaths and emigration of legal immigrants. Finally, MPI adjusts its estimates of the unauthorized immigrant population for recognized undercount in the ACS of this population. For 2020–23, MPI adopted an updated methodology that corrects even more fully for undercount, particularly for new entrants. For more detail on the revised MPI methodology, see Box 2 below and MPI, “MPI Methodology for Assigning Legal Status to Noncitizen Respondents in U.S. Census Bureau Survey Data.” Source: MPI estimates, developed in collaboration with Van Hook.
Most of the changes are expected continuations of trends that started several years ago. For example, the unauthorized immigrant population from Venezuela started to grow quickly following the severe economic and political turbulence that began there in 2015. Likewise, the unauthorized populations from Honduras and Guatemala grew rapidly starting around 2019.
Fluctuating Numbers from Mexico
Even as the numbers of unauthorized immigrants from many nationalities has shown only upward growth, the Mexican unauthorized population has seen ebbs and flows. The Mexican unauthorized population peaked at 7.8 million in 2007. In the wake of the Great Recession of 2008-09, it shrank over several years, hitting a low of 5.3 million in 2021. However, the number of unauthorized Mexican immigrants increased in both 2022 and 2023, reversing the earlier period of decline (see Figure 2), and stood at 5.5 million as of mid-2023.
This increase (especially of families) owes in large measure to the economic instability that occurred in Mexico even as the U.S. economy was strengthening following the COVID-19 pandemic, as well as intervals of internal displacement due to local concentrations of violence, among other factors.
Figure 2. Annual Change in the Size of the U.S. Unauthorized Immigrant Population from Mexico, 2010–23
Note: Data for 2020 were generated using an average of 2019 and 2021 estimates because the 2020 ACS was deemed of low quality due to data-collection difficulties during the first year of the COVID-19 pandemic, leading the U.S. Census Bureau to issue warnings about its use. See U.S. Census Bureau, "Pandemic Impact on 2020 American Community Survey 1-Year Data," updated October 27, 2021. Source: MPI estimates, developed in collaboration with Van Hook.
Why The Sharp Increase?
For many years, the overall unauthorized population hovered around 11 million, plus or minus a few hundred thousand (see Figure 1). This stability occurred because entries were continually offset by exits. For example, during the decade between 2010 and 2019, MPI estimates that roughly 5.9 million people crossed a border illegally or overstayed a visa, while 5.7 million unauthorized immigrants died, emigrated, or, less commonly, obtained legal status—resulting in a net increase of just 200,000 over that period.
However, immigration dynamics changed dramatically starting around 2021, as the U.S. economy recovered faster and more fully from the pandemic-induced downturn than much of the rest of the world and U.S. job opportunities expanded rapidly. At the same time, economic turmoil and episodes of insecurity in Central America and South America, eruptions of gang violence in the Caribbean, and compounding political repression in Cuba, Nicaragua, and Venezuela together fueled new displacement—with some looking northward to the United States.
These increases were met by an overtaxed U.S. migration management system. Over the past few years, huge backlogs in immigration courts, insufficient U.S. government capacity to detain and deport migrants of diverse nationalities, and overall limited resources resulted in several million asylum seekers and other migrants being released into the United States pending long-off court hearings. Smugglers amplified false messages about U.S. policies and migrants’ chances of entering the United States and enticed many to travel irregularly across the Western Hemisphere under increasingly dangerous conditions.
Migrants also entered through the humanitarian parole pathways. In early 2023, the Biden administration created two new humanitarian parole processes: a program permitting Cubans, Haitians, Nicaraguans, and Venezuelans (CHNV) with U.S. sponsors to fly in the United States at their own expense and through the use of the CBP One app allowing migrants to schedule an appointment at a port of entry. These parolees, like the Afghan parolees who came mostly in 2021 and the Ukrainians who came through the Uniting for Ukraine program, were granted one to two years of work authorization and protection from deportation. Such parolees are included in MPI’s estimates of the unauthorized population because their status is temporary and discretionary and does not provide a straightforward path to permanent residence. (In fact, the Trump administration, in January issued a guidance memorandum that would allow immigration authorities to review and consider revoking parole status on a case-by-case basis, making recipients eligible for removal.)
The Growing Diversification in Origins of the Unauthorized Population
Although Mexico continues to be the top origin country, the MPI estimates reveal sizeable shifts in migration patterns that are reshaping the nationality makeup of the overall U.S. unauthorized population. Between 2019 and 2023, the unauthorized immigrant population from Central America increased by 1.7 million, a change that was driven primarily by migration from Honduras and Guatemala. Additionally, the numbers from South America increased by 729,000, primarily due to large-scale migration from Venezuela, Colombia, Ecuador, and Brazil. These increases far outpaced the net growth in the unauthorized population from Mexico, which rose by just 96,000 between 2019 and 2023.
Latin American and Caribbean immigrants combined accounted for 84 percent of all unauthorized immigrants in 2023 (see Table 1).
Table 1. Regions of Birth of Unauthorized Immigrants in the United States, 2010 and 2023
Source: MPI estimates, developed in collaboration with Van Hook.
These diversifying trends mean Mexican immigrants no longer comprise a majority of unauthorized immigrants. In 2010, Mexicans accounted for 62 percent of unauthorized immigrants, but this share declined to just 40 percent by 2023. After Mexico, the top countries of origin of the unauthorized immigrant population for 2023 ranged from those in nearby northern Central America to the South American countries of Venezuela, Colombia, Brazil, and Ecuador; as well as farther-away countries such as India and the Philippines (see Table 2).
Table 2. Top Ten Countries of Origin for the U.S. Unauthorized Immigrant Population, 2010 and 2023
Source: MPI estimates, developed in collaboration with Van Hook.
Continued Growth of a “Twilight” Population
A rising number of people counted in the MPI estimates hold some kind of temporary legal protection— a liminal (also known as “twilight”) status that offers them short-term relief from deportation and access to work authorization. MPI has long counted asylum applicants and holders of Deferred Action for Childhood Arrivals (DACA) or Temporary Protected Status (TPS) in its estimates of the unauthorized population, as have other demographers, and now also includes people with humanitarian parole. While the term unauthorized is an imperfect descriptor for noncitizens whom the U.S. government has granted the right of temporary stay, MPI includes these populations given their lack of a visa or other durable legal status, as well as the impermanence of statuses that could be revoked.
Given that many people hold multiple forms of twilight status at once, it is difficult to know exactly how many of the 13.7 million unauthorized immigrants in 2023 had one or more temporary protections. However, drawing on administrative data, MPI analysts observed that in mid-2023, a maximum of 4 million people—or 29 percent of the overall unauthorized population—held a liminal status (see Table 3). Due to overlap (for example parolees who applied for TPS or asylum, or DACA holders who applied for asylum), the number and share was probably substantially lower.
Table 3. Maximum Number of Individuals Holding a Liminal Immigration Status, Mid-2023
* The asylum applicant number is likely an overestimate because some applicants end up with duplicate or overlapping asylum applications. Notes: The asylum applicants total counts the number of pending asylum applications at U.S. Citizenship and Immigration Services (USCIS) and at immigration courts as of June 30, 2023, inflated upwards to account for the average number of applicants per application for asylum grants in FY 2021–23. Number of TPS and DACA holders reflect an average of numbers actively holding these statuses as of March 30, 2023 and as of September 30, 2023. Number of parole grants sums numbers of people (1) granted parole through the CBP One app process at ports of entry through June 30, 2023, (2) granted parole through the CHNV parole program through June 30, 2023, (3) granted parole through the Uniting for Ukraine program through July 1, 2023, and (4) granted parole through Operation Allies Welcome for Afghans as of March 1, 2023. Some parolees may have subsequently obtained other, more durable statuses. Numbers of grants of Deferred Action counts U visa applicants who were granted deferred action through the bona fide determination process through June 30, 2023, and applicants for Special Immigrant Juvenile Status (SIJS) who were granted deferred action through April 2023. Some of these deferred action grantees may have subsequently obtained SIJS or a U visa. Sources: U.S. Department of Homeland Security (DHS), Office of Homeland Security Statistics (OHSS), “Immigration Enforcement and Legal Processes Monthly Tables,” accessed February 2, 2025; USCIS, “Count of Active DACA Recipients as of March 31, 2023,” accessed February 2, 2025; USCIS, “Count of Active DACA Recipients as of September 30, 2023,” accessed February 2, 2025; Camilo Montoya-Galvez, “U.S. Has Welcomed More than 500,000 Migrants as Part of Historic Expansion of Legal Immigration under Biden,” CBS News, July 18, 2023; Jill H. Wilson, Temporary Protected Status and Deferred Enforced Departure (Washington, DC: Congressional Research Service, July 28, 2023); Jill H. Wilson, Temporary Protected Status and Deferred Enforced Departure (Washington, DC: Congressional Research Service, December 11, 2023); USCIS, “Number of Form I-918 Petitions for U Nonimmigrant Status by Fiscal Year, Quarter, and Case Status, Fiscal Years 2009-2023,” accessed February 2, 2025; USCIS, “Number of Service-wide Forms by Quarter, Form Status, and Processing Time,” various dates; DHS OHSS, “Yearbook of Immigration Statistics, 2021-2023,” accessed February 2, 2025; Executive Office for Immigration Review, “Adjudication Statistics, Total Asylum Applications,” accessed February 2, 2025; panel discussion at the spring conference of the American Immigration Lawyers Association, Washington, DC, April 27–28, 2023.
A Short-Lived Growth Spurt?
Migrant arrivals at the U.S.-Mexico border fell significantly from 2023 to 2024 as result of heightened levels of Mexican enforcement and a series of Biden administration asylum restrictions, suggesting that the growth in the unauthorized immigrant population may have slowed since mid-2023.
Whether this trend continues into 2025 will depend on the actions of the newly inaugurated Trump administration, which is placing high priority on the deportation of large numbers of unauthorized immigrants living in the country and further hardening the U.S.-Mexico border against new arrivals.
Indeed, in its first two weeks, the administration has ended some of the Biden administration’s large humanitarian parole programs and taken new measures seeking to quickly return border entrants to their origin countries. It is also undertaking numerous steps to build the infrastructure necessary to increase deportations from the U.S. interior. However, deportations require extensive resources and collaboration with other governments. And, as noted above, several million unauthorized immigrants have some form of protection or a pending application for protection.
Given these developments, the many push factors that spur migration in the Americas, and the strong U.S. economy, the coming months will tell whether the unauthorized immigrant population will continue to rise beyond 2023, or whether enhanced border enforcement measures and/or deportation efforts succeed in their goals.
Box 2. MPI Methodology and Updates
MPI recently updated its methodology to more accurately account for coverage error of recent immigrants in the Census Bureau’s American Community Survey (ACS). Coverage error occurs when the population is not fully represented in U.S. Census data, and if left unaccounted for, it causes population estimates to be too low. The Census Bureau in December 2024 acknowledged that the ACS in prior years had undercounted recent immigrants, and as a result adjusted its methodology for estimating net international migration.
In the past, MPI’s coverage error assumptions were based on research conducted during the 2000s among Mexican immigrants. This was appropriate when most unauthorized immigrants were from Mexico. In its updated methodology, MPI uses coverage assumptions that can be updated each year and tailored to various national-origin groups.
The updated MPI method adjusts for coverage in two steps. First, newly arrived immigrants have been frequently undercounted in ACS data during their first few years in the United States, so the new MPI method brings the size of newly arrived immigrant cohorts from all national origins into alignment with their (more accurately counted) size at five years of U.S. residency. Second, the method adjusts for additional estimated coverage error by comparing the number of registered births to foreign-born mothers from a given country with the corresponding numbers of births in ACS data. Nearly 100 percent of all births are registered in the United States, so birth registration data can serve as an accurate barometer of the population of mothers and infants across multiple national-origin groups.
The Unauthorized Immigrant Population Expands amid Record U.S.-Mexico Border Arrivals
Amid record encounters of migrants at the U.S.-Mexico border in fiscal years (FY) 2021 and 2022 and wide use of humanitarian parole to allow entry of migrants arriving without visas, the size of the unauthorized immigrant population has reached its highest level yet. The Migration Policy Institute (MPI) estimates that approximately 13.7 million unauthorized immigrants lived in the United States as of mid-2023, up from 12.8 million the year prior. MPI revised upwards its estimates for 2022 and prior years, using an updated methodology that permits better addressing the Census Bureau’s undercount of new immigrants.
Box 1. Measuring and Defining the Unauthorized Immigrant Population
These estimates derive from an updated Migration Policy Institute (MPI) methodology developed in collaboration with a demographer at The Pennsylvania State University that uses administrative data and data from the U.S. Census Bureau’s American Community Survey (ACS) to estimate the size of the unauthorized immigrant population overall, and for top countries and regions of birth. The methodology subtracts the number of legal immigrants of all categories, counted in administrative data, from the total count of the foreign born in the ACS, to estimate the number of unauthorized immigrants. The methodology also adjusts for the fact that the ACS has historically undercounted recently arrived immigrants.
MPI’s definition of the unauthorized immigrant population includes those who entered the country without authorization and visa overstayers, as well as individuals who hold a liminal (or “twilight”) status such as Deferred Action for Childhood Arrivals (DACA), humanitarian parole, or Temporary Protected Status (TPS), as well as those with a pending asylum application.
For a fuller description of MPI’s methodology, see Box 2.
Increase in the Unauthorized Population
Between 2019 and 2023, the unauthorized immigrant population grew by 3 million, or an average of 6 percent per year (see Figure 1). The nation had not seen yearly increases this large since the early 2000s.
This growth is partially explained by increased irregular arrivals at the U.S.-Mexico border, with a rising mix of nationalities from across the Western Hemisphere from countries such as Venezuela, Colombia, Cuba, Ecuador, and Nicaragua, as well as hundreds of thousands of people who entered with humanitarian parole from Ukraine, Mexico, Haiti, and other countries. And it also stems from sizable numbers of Europeans and others who overstayed their nonimmigrant visa.
Figure 1. Estimates of the Size of the U.S. Unauthorized Immigrant Population, 2010–23
Notes: Migration Policy Institute (MPI) estimates of the U.S. unauthorized immigrant population, developed in collaboration with Jennifer Van Hook from The Pennsylvania State University, Population Research Institute, are achieved by subtracting the number of legal immigrants (naturalized citizens, lawful permanent residents, and individuals on long-term nonimmigrant visas) from the total of all foreign-born individuals from major sending countries and regions represented in data from the U.S. Census Bureau’s American Community Survey. The number of legal immigrants is estimated by adding up all legal admissions from each country and region in every year—using U.S. Department of Homeland Security (DHS) administrative data—and then reducing this number to account for deaths and emigration of legal immigrants. Finally, MPI adjusts its estimates of the unauthorized immigrant population for recognized undercount in the ACS of this population. For 2020–23, MPI adopted an updated methodology that corrects even more fully for undercount, particularly for new entrants. For more detail on the revised MPI methodology, see Box 2 below and MPI, “MPI Methodology for Assigning Legal Status to Noncitizen Respondents in U.S. Census Bureau Survey Data.”
Source: MPI estimates, developed in collaboration with Van Hook.
Most of the changes are expected continuations of trends that started several years ago. For example, the unauthorized immigrant population from Venezuela started to grow quickly following the severe economic and political turbulence that began there in 2015. Likewise, the unauthorized populations from Honduras and Guatemala grew rapidly starting around 2019.
Fluctuating Numbers from Mexico
Even as the numbers of unauthorized immigrants from many nationalities has shown only upward growth, the Mexican unauthorized population has seen ebbs and flows. The Mexican unauthorized population peaked at 7.8 million in 2007. In the wake of the Great Recession of 2008-09, it shrank over several years, hitting a low of 5.3 million in 2021. However, the number of unauthorized Mexican immigrants increased in both 2022 and 2023, reversing the earlier period of decline (see Figure 2), and stood at 5.5 million as of mid-2023.
This increase (especially of families) owes in large measure to the economic instability that occurred in Mexico even as the U.S. economy was strengthening following the COVID-19 pandemic, as well as intervals of internal displacement due to local concentrations of violence, among other factors.
Figure 2. Annual Change in the Size of the U.S. Unauthorized Immigrant Population from Mexico, 2010–23
Note: Data for 2020 were generated using an average of 2019 and 2021 estimates because the 2020 ACS was deemed of low quality due to data-collection difficulties during the first year of the COVID-19 pandemic, leading the U.S. Census Bureau to issue warnings about its use. See U.S. Census Bureau, "Pandemic Impact on 2020 American Community Survey 1-Year Data," updated October 27, 2021.
Source: MPI estimates, developed in collaboration with Van Hook.
Why The Sharp Increase?
For many years, the overall unauthorized population hovered around 11 million, plus or minus a few hundred thousand (see Figure 1). This stability occurred because entries were continually offset by exits. For example, during the decade between 2010 and 2019, MPI estimates that roughly 5.9 million people crossed a border illegally or overstayed a visa, while 5.7 million unauthorized immigrants died, emigrated, or, less commonly, obtained legal status—resulting in a net increase of just 200,000 over that period.
However, immigration dynamics changed dramatically starting around 2021, as the U.S. economy recovered faster and more fully from the pandemic-induced downturn than much of the rest of the world and U.S. job opportunities expanded rapidly. At the same time, economic turmoil and episodes of insecurity in Central America and South America, eruptions of gang violence in the Caribbean, and compounding political repression in Cuba, Nicaragua, and Venezuela together fueled new displacement—with some looking northward to the United States.
These increases were met by an overtaxed U.S. migration management system. Over the past few years, huge backlogs in immigration courts, insufficient U.S. government capacity to detain and deport migrants of diverse nationalities, and overall limited resources resulted in several million asylum seekers and other migrants being released into the United States pending long-off court hearings. Smugglers amplified false messages about U.S. policies and migrants’ chances of entering the United States and enticed many to travel irregularly across the Western Hemisphere under increasingly dangerous conditions.
Migrants also entered through the humanitarian parole pathways. In early 2023, the Biden administration created two new humanitarian parole processes: a program permitting Cubans, Haitians, Nicaraguans, and Venezuelans (CHNV) with U.S. sponsors to fly in the United States at their own expense and through the use of the CBP One app allowing migrants to schedule an appointment at a port of entry. These parolees, like the Afghan parolees who came mostly in 2021 and the Ukrainians who came through the Uniting for Ukraine program, were granted one to two years of work authorization and protection from deportation. Such parolees are included in MPI’s estimates of the unauthorized population because their status is temporary and discretionary and does not provide a straightforward path to permanent residence. (In fact, the Trump administration, in January issued a guidance memorandum that would allow immigration authorities to review and consider revoking parole status on a case-by-case basis, making recipients eligible for removal.)
The Growing Diversification in Origins of the Unauthorized Population
Although Mexico continues to be the top origin country, the MPI estimates reveal sizeable shifts in migration patterns that are reshaping the nationality makeup of the overall U.S. unauthorized population. Between 2019 and 2023, the unauthorized immigrant population from Central America increased by 1.7 million, a change that was driven primarily by migration from Honduras and Guatemala. Additionally, the numbers from South America increased by 729,000, primarily due to large-scale migration from Venezuela, Colombia, Ecuador, and Brazil. These increases far outpaced the net growth in the unauthorized population from Mexico, which rose by just 96,000 between 2019 and 2023.
Latin American and Caribbean immigrants combined accounted for 84 percent of all unauthorized immigrants in 2023 (see Table 1).
Table 1. Regions of Birth of Unauthorized Immigrants in the United States, 2010 and 2023
Source: MPI estimates, developed in collaboration with Van Hook.
These diversifying trends mean Mexican immigrants no longer comprise a majority of unauthorized immigrants. In 2010, Mexicans accounted for 62 percent of unauthorized immigrants, but this share declined to just 40 percent by 2023. After Mexico, the top countries of origin of the unauthorized immigrant population for 2023 ranged from those in nearby northern Central America to the South American countries of Venezuela, Colombia, Brazil, and Ecuador; as well as farther-away countries such as India and the Philippines (see Table 2).
Table 2. Top Ten Countries of Origin for the U.S. Unauthorized Immigrant Population, 2010 and 2023
Source: MPI estimates, developed in collaboration with Van Hook.
Continued Growth of a “Twilight” Population
A rising number of people counted in the MPI estimates hold some kind of temporary legal protection— a liminal (also known as “twilight”) status that offers them short-term relief from deportation and access to work authorization. MPI has long counted asylum applicants and holders of Deferred Action for Childhood Arrivals (DACA) or Temporary Protected Status (TPS) in its estimates of the unauthorized population, as have other demographers, and now also includes people with humanitarian parole. While the term unauthorized is an imperfect descriptor for noncitizens whom the U.S. government has granted the right of temporary stay, MPI includes these populations given their lack of a visa or other durable legal status, as well as the impermanence of statuses that could be revoked.
Given that many people hold multiple forms of twilight status at once, it is difficult to know exactly how many of the 13.7 million unauthorized immigrants in 2023 had one or more temporary protections. However, drawing on administrative data, MPI analysts observed that in mid-2023, a maximum of 4 million people—or 29 percent of the overall unauthorized population—held a liminal status (see Table 3). Due to overlap (for example parolees who applied for TPS or asylum, or DACA holders who applied for asylum), the number and share was probably substantially lower.
Table 3. Maximum Number of Individuals Holding a Liminal Immigration Status, Mid-2023
* The asylum applicant number is likely an overestimate because some applicants end up with duplicate or overlapping asylum applications.
Notes: The asylum applicants total counts the number of pending asylum applications at U.S. Citizenship and Immigration Services (USCIS) and at immigration courts as of June 30, 2023, inflated upwards to account for the average number of applicants per application for asylum grants in FY 2021–23. Number of TPS and DACA holders reflect an average of numbers actively holding these statuses as of March 30, 2023 and as of September 30, 2023. Number of parole grants sums numbers of people (1) granted parole through the CBP One app process at ports of entry through June 30, 2023, (2) granted parole through the CHNV parole program through June 30, 2023, (3) granted parole through the Uniting for Ukraine program through July 1, 2023, and (4) granted parole through Operation Allies Welcome for Afghans as of March 1, 2023. Some parolees may have subsequently obtained other, more durable statuses. Numbers of grants of Deferred Action counts U visa applicants who were granted deferred action through the bona fide determination process through June 30, 2023, and applicants for Special Immigrant Juvenile Status (SIJS) who were granted deferred action through April 2023. Some of these deferred action grantees may have subsequently obtained SIJS or a U visa.
Sources: U.S. Department of Homeland Security (DHS), Office of Homeland Security Statistics (OHSS), “Immigration Enforcement and Legal Processes Monthly Tables,” accessed February 2, 2025; USCIS, “Count of Active DACA Recipients as of March 31, 2023,” accessed February 2, 2025; USCIS, “Count of Active DACA Recipients as of September 30, 2023,” accessed February 2, 2025; Camilo Montoya-Galvez, “U.S. Has Welcomed More than 500,000 Migrants as Part of Historic Expansion of Legal Immigration under Biden,” CBS News, July 18, 2023; Jill H. Wilson, Temporary Protected Status and Deferred Enforced Departure (Washington, DC: Congressional Research Service, July 28, 2023); Jill H. Wilson, Temporary Protected Status and Deferred Enforced Departure (Washington, DC: Congressional Research Service, December 11, 2023); USCIS, “Number of Form I-918 Petitions for U Nonimmigrant Status by Fiscal Year, Quarter, and Case Status, Fiscal Years 2009-2023,” accessed February 2, 2025; USCIS, “Number of Service-wide Forms by Quarter, Form Status, and Processing Time,” various dates; DHS OHSS, “Yearbook of Immigration Statistics, 2021-2023,” accessed February 2, 2025; Executive Office for Immigration Review, “Adjudication Statistics, Total Asylum Applications,” accessed February 2, 2025; panel discussion at the spring conference of the American Immigration Lawyers Association, Washington, DC, April 27–28, 2023.
A Short-Lived Growth Spurt?
Migrant arrivals at the U.S.-Mexico border fell significantly from 2023 to 2024 as result of heightened levels of Mexican enforcement and a series of Biden administration asylum restrictions, suggesting that the growth in the unauthorized immigrant population may have slowed since mid-2023.
Whether this trend continues into 2025 will depend on the actions of the newly inaugurated Trump administration, which is placing high priority on the deportation of large numbers of unauthorized immigrants living in the country and further hardening the U.S.-Mexico border against new arrivals.
Indeed, in its first two weeks, the administration has ended some of the Biden administration’s large humanitarian parole programs and taken new measures seeking to quickly return border entrants to their origin countries. It is also undertaking numerous steps to build the infrastructure necessary to increase deportations from the U.S. interior. However, deportations require extensive resources and collaboration with other governments. And, as noted above, several million unauthorized immigrants have some form of protection or a pending application for protection.
Given these developments, the many push factors that spur migration in the Americas, and the strong U.S. economy, the coming months will tell whether the unauthorized immigrant population will continue to rise beyond 2023, or whether enhanced border enforcement measures and/or deportation efforts succeed in their goals.
Box 2. MPI Methodology and Updates
MPI recently updated its methodology to more accurately account for coverage error of recent immigrants in the Census Bureau’s American Community Survey (ACS). Coverage error occurs when the population is not fully represented in U.S. Census data, and if left unaccounted for, it causes population estimates to be too low. The Census Bureau in December 2024 acknowledged that the ACS in prior years had undercounted recent immigrants, and as a result adjusted its methodology for estimating net international migration.
In the past, MPI’s coverage error assumptions were based on research conducted during the 2000s among Mexican immigrants. This was appropriate when most unauthorized immigrants were from Mexico. In its updated methodology, MPI uses coverage assumptions that can be updated each year and tailored to various national-origin groups.
The updated MPI method adjusts for coverage in two steps. First, newly arrived immigrants have been frequently undercounted in ACS data during their first few years in the United States, so the new MPI method brings the size of newly arrived immigrant cohorts from all national origins into alignment with their (more accurately counted) size at five years of U.S. residency. Second, the method adjusts for additional estimated coverage error by comparing the number of registered births to foreign-born mothers from a given country with the corresponding numbers of births in ACS data. Nearly 100 percent of all births are registered in the United States, so birth registration data can serve as an accurate barometer of the population of mothers and infants across multiple national-origin groups.
As a result of these adjustments, MPI has revised upwards from its earlier estimates the size of the unauthorized immigrant population in 2021-23. For more on the methodology, see “MPI Methodology for Assigning Legal Status to Noncitizen Respondents in U.S. Census Bureau Survey Data.”