Record-high numbers of migrants have attempted to cross into the US border. Data on these border encounters, which refers to unauthorized or denied entries into the country, plays an important role in helping the government estimate the number of individuals illegally entering the US.

By understanding the demographics and origins of people encountered at the border, policymakers can gain a clearer understand of the complex factors driving immigration and shape informed policy decisions.

What is the definition of a border encounter?

The Department of Homeland Security separates border encounters into three categories:

  • Apprehensions are the temporary detainment of people by the US Border Patrol (USBP) who crossed the border illegally between ports of entry. They may or may not be arrested under Title 8. These individuals are able to file for asylee status.
  • Inadmissibles are individuals encountered at ports of entry by officers of the Office of Field Operations (OFO) seeking lawful admission into the United States but are found ineligible for entry under Title 8. These can also include people seeking humanitarian protection and people who voluntarily withdraw their admission application.
  • Expulsions refer to migrants denied exclusively through Title 42 to stop the spread of COVID-19, and only applies from March 2020 to May 2023. They were encountered by either USBP or OFO officers and returned to their country of last transit or home country.

These encounters do not necessarily correspond to the number of people attempting to cross the border since the people can make multiple attempts to cross the border within the same fiscal year.

Also, a single border encounter can encompass groups of different sizes, ranging from entire families or single individuals, and still register as only a single incident, meaning the term “encounters” should not be conflated with “people.”

What is illegal immigration?

Undocumented immigrants, sometimes called illegal aliens, are foreign-born individuals who lack a valid visa or other necessary immigration documentation due to entering the U.S. without inspection, exceeding the allowed duration of their temporary visa, or breaching the terms of their admission.

On the other hand, documented, or legal, immigrants are individuals born in foreign countries who have attained legal status to enter and live in the United States.

How many border encounters occur each year?

Between October 2019 and June 2023, the US Customs and Border Protection (CBP) office reported almost 7.7 million border encounters across the US. Monthly encounters peaked at over 300,000 people in December 2022.

For comparison, average annual apprehensions rose from approximately 394,000 between fiscal years 2010 and 2018 to 658,315 between fiscal years 2020 and 2022.

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Border encounters dropped slightly between March and April 2020. During this time, former President Donald Trump’s administration invoked Title 42 to authorize border expulsions in the interest of public health during the pandemic.

The Title 42 public health order ended in May 2023, meaning border patrol officers could no longer expel illegal migrants for COVID-19-related reasons.

Although the pandemic initially appeared to lower border encounters, they gradually rebounded over 2020. Notably, these encounters surged by 66% between February and March 2021, and have since remained at an elevated level.

While there isn’t any definitive data on the inflow of undocumented immigrants, border encounters serve as a helpful, if imperfect, proxy. This data helps the Office of Immigration Statistics model what proportion of illegal entries are prevented by apprehensions, captured by the at-the-border apprehension rate.

Despite the relatively high number of encounters in 2021, the CBP’s improved estimated at-the-border apprehension rate averaged 78% from 2018 to 2020, compared to 35% from 2002 to 2004. This resulted in fewer entries without inspection than in the early 2000s.

According to preliminary estimates at the time, approximately 660,000 people crossing the border evaded apprehension in fiscal year 2021. While this was an increase compared to seen from 2014 to 2020 (160,000 per year), it was still lower than any year from 2000 to 2010 and only one-third as high as estimates for 2000 to 2006.

Who is encountered at the border?

According to the CBP, roughly 80% of people apprehended or denied entry between October 2019 and June 2023  were Latin American citizens. More than 30% came from Mexico, followed by Honduras (9.2%), Guatemala (9.0%), Venezuela (5.8%), and Cuba (5.8%).

A table with a bar chart depicting the number of total border encounters by country of citizenship between FY 2020 and June 2023 in descending order, beginning with Mexico at nearly 2.4 million encounters.

Border encounters have risen for all nations monitored by the CBP since 2019. However, the numbers can vary over time based on each country’s unique political and economics dynamics, travel distances, and factors influencing migration patterns.

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Not everyone who crosses into the US is attempting to immigrate. Other reasons could include various criminal activities, such as drug or human trafficking, or other smuggling-related acts.

Which states do migrants attempt to cross into?

While illegal border encounters occur all over the country, including non-border states, 82.8% of cases between October 2019 and June 2023 occurred along the US-Mexico border.

Texas had 49.6% of nationwide border encounters within its territory, followed by Arizona at 17.9%, and California at 14.0%.

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How many border encounters involve children?

Between October 2019 and June 2023, nearly 450,000 border encounters included children. The majority of child encounters, at 96.5%, are unaccompanied children, with roughly 16,000, or 3.5%, made up of accompanied minors.

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Within this period, over 70% of the people the CBP encountered were single adults. The proportion of encounters with whole family units (categorized as FMUA) doubled between fiscal years 2020 and 2021 from 11.6% to 24.7% of total cases.

Where does this data come from?

All data included in this article comes from US Customs and Border Protection’s data on nationwide encounters.

Nationwide encounters include the sum of CBP encounters across all areas of responsibility. This includes the northern land border, the southwest land border, the OFO non-land border ports of entry (such as airports and seaports), and the USBP sectors that do not share a land border (such as Florida or New York).

How does the department of Homeland Security estimate illegal border crossings?

According to an August 2020 CBP report, the Department of Homeland Security estimates unauthorized border crossings by collecting data from various sources, including border encounters and refugee and asylee figures, as well as migrant sample surveys, interviews, and other statistical methodologies.

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Nationwide Encounters
Last updated
July 18, 2023