The number of undocumented immigrants living in the United States has become one of the most closely watched figures in American public policy. It influences debates over border security, employment, housing, public spending, immigration reform, and the future of communities across the country. Yet finding a precise answer to the question “How many undocumented immigrants are in the US?” is more complicated than looking up a government statistic.

Unlike the total U.S. population, the undocumented immigrant population is not counted through a simple national registration system. Researchers must combine census information, immigration records, demographic surveys, and estimates of people who have obtained legal status or left the country.

The available research suggests that the population reached historically high levels in recent years, although immigration patterns and government policies have continued to change the picture.

The Estimated Number of Undocumented Immigrants in the United States

There is no single official count that captures every undocumented immigrant currently living in the United States.

One of the most important recent estimates comes from the Migration Policy Institute (MPI). In a report released in July 2026, MPI estimated that approximately 15.8 million unauthorized immigrants were living in the United States in mid-2024. This represented a substantial increase compared with the population estimates recorded during much of the previous decade.

Pew Research Center published another widely cited estimate in August 2025. Its research placed the unauthorized immigrant population at approximately 14 million in 2023, the highest level in its historical estimates at that time.

These figures are not contradictory. They refer to different years and come from different research analyses. They also illustrate how quickly immigration patterns can change.

The following figures provide some historical context:

The figures show that unauthorized immigration has not followed a straight upward path. The population increased rapidly during the 1990s and early 2000s, declined over the following decade, and then experienced another significant increase after 2021.

It is important to distinguish estimates for different years rather than treating the latest published figure as an exact count of people currently living in the country.

Why Is It Difficult to Count Undocumented Immigrants?

The U.S. Census Bureau does not ask every resident to provide proof of immigration status. Its population surveys are designed to count people living in the country, not to establish whether each person has legal authorization to remain.

Researchers therefore use an approach commonly known as the residual method.

In simple terms, they estimate the total foreign-born population and subtract the number of people believed to have lawful immigration status. The remaining population provides an estimate of unauthorized immigrants.

This process involves several sources of information, including:

• American Community Survey data.

• Census Bureau population estimates.

• Immigration and naturalization records.

• Refugee and asylum statistics.

• Temporary visa and residency information.

• Research into migration patterns and departures from the United States.

There are limitations. Some people may not participate in government surveys, while others may be difficult to classify because their immigration status has changed.

For example, someone who entered the United States without authorization may later receive temporary protection or obtain another form of immigration relief. Researchers must account for these changes when calculating population estimates.

This explains why different research organizations can publish different figures without necessarily making a statistical error.

Where Do Most Undocumented Immigrants Live?

Undocumented immigrants are not distributed evenly throughout the United States. Some states have considerably larger populations because of employment opportunities, established immigrant communities, geographic location, and family connections.

According to Pew Research Center's 2023 estimates, the states with the largest unauthorized immigrant populations included:

California and Texas have traditionally been major destinations for international migrants. Their large economies, extensive labor markets, and established immigrant communities have helped maintain their positions among the states with the largest undocumented populations.

Florida has also experienced substantial growth. Its construction, hospitality, agriculture, and service industries provide employment opportunities for workers from different parts of the world.

However, immigration is no longer concentrated exclusively in a small number of traditional destination states. More immigrants have settled in the Southeast, Midwest, and other parts of the country.

For local housing markets and businesses, this geographic distribution can be just as important as the national total.

Which Countries Do Undocumented Immigrants Come From?

Mexico has historically been the largest country of origin for undocumented immigrants in the United States. However, the composition of this population has changed considerably.

Pew Research Center's research indicates that the Mexican share of the unauthorized immigrant population fell from approximately 62% in 2010 to 35% in 2023.

Immigration from Central America, South America, the Caribbean, and other regions has become increasingly significant.

Countries including Venezuela, Cuba, Colombia, Nicaragua, Haiti, and Ecuador have contributed to the changing demographic profile.

Economic instability, political uncertainty, limited employment opportunities, family reunification, and security concerns are among the factors influencing migration decisions.

The changing origins of immigrants also affect where newcomers settle. People frequently choose locations where relatives, friends, or established communities can help them find accommodation and employment.

How Do Undocumented Immigrants Affect the U.S. Economy?

Immigration is often discussed as a political issue, but its economic implications are equally important.

Undocumented immigrants participate in a wide range of industries. These include construction, agriculture, food processing, hospitality, transportation, landscaping, and household services.

Pew Research Center estimated that approximately 9.7 million unauthorized immigrants were part of the U.S. labor force in 2023, representing around 5.6% of all workers.

In some industries and regions, their contribution is particularly visible.

Construction is one example. Residential building, renovation, roofing, landscaping, and other property-related services depend on large numbers of workers. Labor shortages can affect project schedules, construction costs, and the availability of housing.

Agriculture is another important sector. Farms across the country rely on seasonal and year-round workers to plant, harvest, process, and distribute food.

Undocumented immigrants also contribute to consumer spending. They pay rent, purchase groceries, use transportation services, and spend money in local businesses.

Their economic impact is not entirely positive or negative. It varies according to local labor conditions, public service capacity, tax arrangements, and immigration policy.

A realistic discussion needs to consider both the economic contributions of immigrant workers and the challenges associated with an expanding population.

What Is the Difference Between Undocumented and Illegal Immigrants?

The terms undocumented immigrants, unauthorized immigrants, and illegal immigrants are frequently used in American media and political discussions.

Although they often refer to overlapping groups, their wording is not identical.

An undocumented immigrant generally refers to someone who does not have the required immigration documentation or lawful status to reside in the United States.

An unauthorized immigrant is a broader research term frequently used by organizations such as Pew Research Center and the Migration Policy Institute. It can include people who entered the country without inspection, overstayed a visa, or otherwise lack permanent lawful immigration status.

The term illegal immigrant is more politically charged and is often used in public debate.

It is also important to understand that not everyone who enters the United States legally has permanent immigration status. Some people enter through temporary programs or receive certain forms of protection while their immigration cases are pending.

For this reason, immigration researchers generally prefer to explain the specific legal categories being measured rather than assuming that every person without permanent residency has the same circumstances.

How Could Immigration Enforcement Change These Numbers?

Immigration enforcement has become a major factor influencing population estimates.

The number of undocumented immigrants can change through several different processes. New arrivals may increase the population, while deportations, voluntary departures, deaths, and adjustments to lawful immigration status can reduce it.

Changes in asylum policies, humanitarian parole programs, temporary protected status, and border enforcement can also influence the figures.

Pew Research Center's August 2025 analysis suggested that the unauthorized immigrant population may have started declining during the first half of 2025. However, the organization emphasized that available data was incomplete and could not establish an exact national total for that period.

This distinction matters because border encounters, deportation numbers, and the estimated population living in the United States measure different things.

For example, a border encounter is not necessarily equivalent to a person permanently entering the country. Some individuals may be encountered more than once, while others may be released, returned, or processed under different immigration procedures.

Consequently, adding annual border encounter figures to an existing population estimate does not produce an accurate count of undocumented immigrants.

Future population trends will depend on enforcement priorities, economic conditions, immigration legislation, and the number of people entering or leaving the country.

The Connection Between Immigration and the U.S. Housing Market

Immigration also has a relationship with housing demand, particularly in metropolitan areas experiencing rapid population growth.

People arriving in the United States need somewhere to live. Some rent apartments, others share accommodation with relatives, and some eventually purchase residential property after establishing their financial and legal circumstances.

When population growth outpaces housing construction, additional demand can put pressure on rental markets.

This does not mean undocumented immigrants are the primary reason for high housing costs. Home prices and rents are influenced by many other factors, including mortgage rates, construction expenses, zoning restrictions, available land, household formation, and regional employment growth.

Nevertheless, population changes are an important part of understanding housing demand.

For property investors, developers, and real estate professionals, immigration trends can provide useful information about future rental demand, workforce availability, and the growth of local communities.

The effects are especially relevant in metropolitan areas such as Los Angeles, Houston, Miami, New York, and Orlando, where population movements and economic development can influence residential property markets.

What Should We Expect in the Coming Years?

The undocumented immigrant population in the United States is likely to remain a significant subject of national debate.

The 15.8 million estimate published by MPI for mid-2024 and Pew Research Center's 14 million estimate for 2023 demonstrate the scale of the population, but neither should be mistaken for an exact count in November 2026.

The direction of future change will depend on several factors: immigration enforcement, border policies, economic opportunities, legal immigration pathways, and the ability of the government to process immigration applications.

There is also a longer-term demographic question. The United States has an aging population and continuing demand for workers in several industries. Immigration policy will therefore have implications beyond border security, affecting employment, business development, population growth, and housing demand.

Understanding these connections requires looking beyond political headlines and examining reliable population data.

For anyone interested in the U.S. economy, real estate, or international migration, the number of undocumented immigrants is more than a political statistic. It is one measure of the demographic changes shaping the country.