Primer on U.S. Immigration Policy

Summary

The executive branch may exercise statutory or executive authority to allow certain noncitizens to enter or remain in the United States on a time-limited basis, including those who have not been admitted through permanent or temporary pathways under the INA and might otherwise be subject to removal. These include Temporary Protected Status (TPS), immigration parole, and Deferred Action for Childhood Arrivals (DACA).

Introduction

In general, nonresident foreign nationals who wish to come to the United States—either as lawful permanent residents (LPRs) through permanent family-sponsored, employment-based, and diversity categories; or as nonimmigrants through temporary pathways—must obtain a visa from a U.S. consulate.³ Immigrant visas provide for permanent residence; nonimmigrant visas provide for temporary stays. A visa permits a foreign national to travel to a U.S. port of entry and request permission from CBP to enter the country (i.e., apply for admission). In addition, to obtain a visa a foreign national must establish that he/she meets the requirements for the specific visa classification. Consular officers can deny visas under three main INA provisions:

• 1. insufficient information under INA Section 221(g),
• 2. grounds of inadmissibility under INA Section 212(a), and
• 3. for nonimmigrant applicants, the INA Section 214(b) presumption of seeking permanent residence.

A visa denial under INA Section 221(g) indicates that the DOS consular officer abroad lacks sufficient information to determine if a foreign national is eligible to receive a visa. A consular officer may also disqualify a visa applicant if (1) he/she knows or has reason to believe the alien is inadmissible under INA Section 212(a) (described below) or any other provision of law, or (2) the application fails to comply with INA provisions or regulations. A visa denial under INA Section 214(b) indicates that the foreign national was unable to demonstrate to the consular officer that he/she had sufficient ties to his/her home country to return home.⁴ This is the most common reason that DOS denies nonimmigrant visas.

Consular officers must decide whether a foreign national may be denied admission to the United States under the grounds in INA Section 212(a), which include the following:

The INA describes procedures for making and reviewing an inadmissibility determination and specifies conditions under which some of these provisions may be waived.

All visa applicants are required to submit their photograph, fingerprints, and biographic information. Visa applicants are checked against multiple databases and information sources for security purposes. All prospective LPRs and certain prospective nonimmigrants must also submit to physical and mental examinations. Visa applicants generally must be interviewed by a consular officer in person to determine whether they are qualified to receive a visa.⁹ Consular officers' decisions on whether or not to grant foreign nationals a visa are not subject to judicial appeals. Visa applicants who were denied a visa for a particular ineligibility and meet certain conditions may apply to DHS for a waiver of that ineligibility and apply again for a visa.

The INA has civil enforcement provisions, distinct from removal or inadmissibility proceedings, to prosecute individuals and entities that engage in immigration document fraud.¹⁰ Apart from the INA, the U.S. Criminal Code classifies knowingly producing or using fraudulent immigration documents (e.g., visas, border crossing cards) as criminal offenses.¹¹

Category

Individuals in Category

Numerical Limit

Immediate Relatives

Spouses and unmarried minor children of U.S. citizens, and parents of adult U.S. citizens

Unlimited

Preference Immigrants

226,000 (floor)

1^st Preference

Unmarried adult children of U.S. citizens

23,400 plus unused 4^th preference visas

2^nd Preference

(A) Spouses and minor children of LPRs

114,200 plus unused 1^st preference visas (with at least 77% reserved for 2^nd [A] subgroup)

(B) Unmarried adult children of LPRs

3^rd Preference

Married adult children of U.S. citizens

23,400 plus unused 1^st or 2^nd preference visas

4^th Preference

Siblings of adult U.S. citizens

65,000 plus unused 1^st, 2^nd, or 3^rd preference visas

Category

28.6% of total EB limit (40,040) plus unused 4^th and 5^th preference visas

2^nd Preference

28.6% of total EB limit (40,040) plus unused 1^st preference visas

3^rd Preference

28.6% of total EB limit (40,040) plus unused 1^st or 2^nd preference visas; "other workers" limited to 10,000.

4^th Preference

Special immigrants, including ministers of religion, religious workers other than ministers, certain employees of the U.S. government abroad, and others

5^th Preference

Employment creation investors who invest at least $1.05 million ($800,000 in rural areas, areas of high unemployment, or infrastructure projects) and create/preserve at least 10 U.S. jobs

7.1% of total limit (9,940); 3,000 minimum reserved for investors in rural or high unemployment areas

Source: INA §203(b), 8 U.S.C. §1153(b).

An asylee is a person who meets the definition of a refugee in terms of persecution or a well-founded fear of persecution but is present in the United States or at a land border or port of entry to the United States.³⁵ Under the INA, aliens who are physically present in the United States or who arrive in the United States may apply for asylum regardless of their immigration status, subject to certain restrictions.³⁶ A person who is not in removal proceedings may apply for affirmative asylum with USCIS.³⁷ Persons in removal proceedings may apply for defensive asylum (i.e., asylum as a defense against removal) in immigration court (within DOJ's EOIR).³⁸ Grants of asylum are not numerically limited. Asylees may apply for LPR status one year after being granted asylum. ³⁹ There are no numerical limits on status adjustments for asylees.

Under the INA, eligible LPRs may become U.S. citizens through the naturalization process.⁴⁸ With some exceptions,⁴⁹ naturalization applicants must have resided continuously in the United States as LPRs for five years (three years for the spouses of U.S. citizens⁵⁰) and demonstrate good moral character during the statutory period.

An individual may apply to naturalize by filing an application with USCIS and completing a biometric-based background check. Applicants then undergo an interview with USCIS during which they answer questions about their application and background and take English and civics tests. Those whose applications are approved become U.S. citizens after taking the Oath of Allegiance in a naturalization ceremony.

There are no numerical limits on naturalizations. In FY2024, USCIS naturalized 818,500 U.S. citizens.⁵¹ In 2023, an estimated 25 million naturalized citizens resided in the United States, comprising 52% of the estimated 47.8 million foreign-born U.S. residents.⁵² As of January 2024, an estimated 8.7 million LPRs were potentially able to naturalize based on having met age and residency requirements.⁵³

A naturalized citizen may have his/her citizenship revoked on the basis that the citizenship was procured illegally, by concealment of material fact, or by willful misrepresentation.⁵⁴

Some nonimmigrant categories have annual numerical limits; others do not.⁵⁸ In FY2023, DOS issued 10.4 million nonimmigrant visas, with the largest number of visa issuances to B-1 business visitors and B-2 tourists (57%); border crossing card (BCC) holders (17%); H-2A, H-2B, and H-1B temporary workers (7%); F-1 foreign students (4%); C-1/D transit/crew members (3%); and J-1 cultural exchange visitors (3%).⁵⁹

The Visa Waiver Program (VWP) allows citizens of 42 participating countries (or jurisdictions)—which must meet a number of qualifying criteria—to enter the United States as temporary visitors for business or pleasure without visas.⁶³ In FY2023, roughly 15.4 million pleasure and 2 million business visitors entered the United States using the VWP.⁶⁴

When extraordinary conditions such as civil unrest, violence, or natural disasters occur in foreign countries, foreign nationals from those places who are present in the United States may not be able to return home safely. The INA allows the DHS Secretary to designate countries for TPS for periods of 6, 12, or 18 months at a time.⁶⁶ Congress has also provided TPS legislatively. As of September 2024, there were approximately 1.1 million individuals in the United States with TPS.⁶⁷ As of the cover date of this report, 17 countries were designated for TPS: Afghanistan, Burma, Cameroon, El Salvador, Ethiopia, Haiti, Honduras, Lebanon, Nepal, Nicaragua, Somalia, South Sudan, Sudan, Syria, Ukraine, Venezuela, and Yemen.

Nationals of designated countries already present in the United States may apply for TPS. Individuals granted TPS are eligible for employment authorization, cannot be detained on the basis of their immigration status, and are not subject to removal while they retain TPS. TPS does not provide a recipient with a designated pathway to LPR status; however, a TPS recipient is not barred from acquiring a lawful immigration status (e.g., asylum, nonimmigrant status, LPR status) if he/she meets the requirements.

Applicants apply for TPS with USCIS according to deadlines set in the Federal Register notices that announce each TPS designation or extension. These notices specify the dates by which individuals must have continuously resided in the United States in order to qualify. Foreign nationals outside the United States are not eligible for TPS.

DED may be authorized by the President based on the executive branch's independent constitutional authority rather than any specific statutory authority. It provides a temporary, discretionary, administrative stay of removal to foreign nationals from designated areas. The Administration may use its discretion when applying DED to a particular area by balancing foreign policy, humanitarian, and immigration concerns. DED grants are announced for set periods of time at the President's discretion and may be extended. As of the cover date of this report, certain Palestinians, Lebanese, Liberians, and residents of Hong Kong living in the United States maintain protection under DED. ⁶⁸ Covered individuals may apply for work authorization but they are not required to apply for DED; DED is triggered during removal proceedings.

The INA authorizes DHS, on a case-by-case basis, to parole an alien into the United States for urgent humanitarian reasons or significant public benefit at its discretion.⁶⁹ Foreign nationals may request parole inside or outside the United States. Parole is granted for a specified period and does not constitute formal admission to the United States. A parole grant generally does not provide a dedicated path to LPR status.⁷⁰ Persons granted parole (parolees) may obtain employment authorization. Those granted parole must depart the United States when the parole expires or, if eligible, be admitted in a lawful status. Parolees may also apply for re-parole.⁷¹

In recent years, the use of parole processes for specific populations (e.g., special processes set up during the Biden Administration for nationals of Ukraine, Cuba, Haiti, Nicaragua, and Venezuela) have been subject to debate. As of the cover date of this report, many of these processes have been terminated or paused by the Trump Administration.⁷²

Under the DACA initiative, established by executive action in 2012, certain individuals without a lawful immigration status who were brought to the United States as children and meet other criteria have been granted deferred action for two years, subject to renewal. DACA eligibility is based on requirements related to age, U.S. residence, education, and criminal history as established in a June 15, 2012, DHS memorandum.⁷³ Deferred action is "a type of prosecutorial discretion that allows an individual to remain in the United States for a set period of time."⁷⁴

To qualify for DACA, an individual must have been under age 31 as of June 15, 2007 (the issue date of the memorandum), physically present in the United States, entered the United States no later than five years before the memorandum's issue date, and have been continuously resident since then. In addition, the individual must have been under age 16 at the time of initial entry. As of the end of FY2024, there were 537,730 active DACA recipients.⁷⁵

Like those covered by TPS, DED, and granted parole, DACA recipients can apply for employment authorization but have no dedicated path to LPR status. DACA has been subject to ongoing litigation challenging its legality but remains in effect as of the cover date of this report.⁷⁶ Currently, USCIS processes only DACA renewal applications and accompanying applications for employment authorization; it does not process initial DACA requests from individuals who have never had DACA.⁷⁷

In recent years, CBP has had record-high levels of enforcement encounters at the Southwest border. Encounters have reflected a diverse array of national origins and a relatively high rate of children and families, many seeking asylum.⁹¹ Border enforcement encounters began to slow at the end of FY2024.⁹²

Although CBP is primarily responsible for border enforcement, other agencies also play a role; including ICE, which provides transportation support and detention space and carries out removals; and ORR, which is responsible for the care and custody of unaccompanied alien children apprehended at the border.⁹³

ICE's Enforcement and Removal Operations (ERO) is responsible for interior immigration enforcement, which involves the identification, apprehension, detention, supervision, transportation, and removal of aliens who violate U.S. immigration laws. These may include aliens who entered the United States without inspection, overstayed a nonimmigrant visa, or otherwise violated the terms of a lawful admission. DHS has prosecutorial discretion to set civil immigration enforcement priorities, which may vary over time and across Administrations.⁹⁴

ERO operates programs to identify criminal and other removable aliens, including the Criminal Alien Program (CAP),⁹⁵ which "identifies, locates and arrests noncitizens in the custody of other law enforcement agencies, as well as those noncitizens released from other law enforcement agencies who were arrested for criminal activity."⁹⁶ CAP includes a data sharing infrastructure, or interoperability, between DHS and DOJ that screens for both immigration and criminal violations when individuals are booked into prisons or jails that participate in the program. To pursue known at-large criminal aliens and fugitive aliens outside of controlled settings (i.e., administrative offices or custodial settings), ICE uses the National Fugitive Operations Program. ICE's Section 287(g) program allows DHS to delegate certain immigration enforcement functions to specially trained state and local law enforcement officers, under federal supervision.⁹⁷

ICE's interior enforcement responsibility includes worksite enforcement, which is conducted by ICE's Homeland Security Investigations (HSI) directorate. The INA prohibits an employer from knowingly hiring, recruiting or referring for a fee, or continuing to employ an alien who lacks work authorization.⁹⁸ Employers who violate prohibitions on unauthorized employment may be subject to civil monetary penalties and/or criminal penalties.

In FY2024, apprehended aliens were held in 129 ERO detention facilities.¹⁰⁰ That year, ERO primarily detained aliens apprehended by CBP at the Southwest border and transferred to ICE custody, and aliens with criminal histories apprehended by ERO in the U.S. interior. ICE detained 37,684 persons at the end of FY2024.¹⁰¹ Detention capacity is controlled largely through funding made available in congressional appropriations. Because detention capacity is limited, ICE may prioritize detaining certain populations (e.g., those subject to mandatory detention under the INA, those considered public safety or national security threats, and flight risks).¹⁰²

ICE also manages a non-detained docket of individuals released from custody who are awaiting removal proceedings or subject to final orders of removal. At the end of FY2024, there were 7.6 million people on the non-detained docket, a nearly 25% increase from FY2023.¹⁰³ Some individuals on the non-detained docket are supervised under ERO's Alternatives to Detention (ATD) program. This program allows ICE to monitor certain aliens subject to removal who have been released into the United States, using technology (e.g., mobile applications, ankle monitors) and case management options (e.g., home visits, virtual check-ins).¹⁰⁴ ICE reported 179,000 ATD participants as of the end of FY2024.¹⁰⁵

Aliens with a final removal order must generally be removed by DHS within 90 days, during which time they may be detained.¹¹³ Individuals with a final order of removal may be repatriated by DHS to their country of citizenship or to a third country. This process requires cooperation from the country designated for removal, which must confirm the individual's nationality, issue travel documents, and accept their physical return. Under a 2001 Supreme Court decision (Zadvydas v. Davis), detained aliens subject to removal orders but for whom there is "no significant likelihood of removal in the reasonably foreseeable future" must be released into the United States after six months, with limited exceptions.¹¹⁴ DHS considers countries that refuse or delay the repatriation of their citizens to be recalcitrant or uncooperative.¹¹⁵ Foreign nationals who have been removed generally are ineligible to return to the United States for a minimum of five years.¹¹⁶

INA provisions permit certain removable aliens to remain in the United States, either permanently or temporarily. Some of these options have already been described in previous sections of this report. Options that provide permanent relief by conferring or leading to LPR status include cancellation of removal (see the "Other Pathways to LPR Status" section) and defensive asylum applied for during removal proceedings (see the "Refugees and Asylees" section).¹¹⁷ Individuals may also obtain temporary protection from removal through TPS, DED, and DACA (see the "Discretionary Permissions to Enter or Remain in the United States" section). Additional options that provide temporary relief from removal include withholding of removal, Convention Against Torture (CAT) protection, and deferred action.

Withholding of removal may be granted to foreign nationals who can demonstrate that it is more likely than not that if removed to their home country they would be persecuted on account of their race, religion, nationality, membership in a particular social group, or political opinion. Like asylum, withholding of removal protects people from removal to a country where they fear persecution. Withholding of removal is granted by an EOIR immigration judge. Unlike asylum, an immigration judge has no discretion and must grant withholding of removal to applicants who meet the requirements.¹¹⁸ In addition, to be granted withholding of removal, applicants must prove that it is "more likely than not" that they will be persecuted based on a protected ground.¹¹⁹

CAT protection may be granted by an immigration judge to individuals who fear torture in their home country. To qualify, applicants must demonstrate that it is more likely than not that they will be tortured directly by or with the acquiescence of the government of their country of origin.¹²⁰ Withholding of removal and CAT protection provide no path to LPR status and allow for possible removal to a third country.¹²¹

Deferred action is a form of prosecutorial discretion exercised by DHS that temporarily defers removal against a covered individual.¹²² Examples of deferred action may include DHS terminating removal proceedings, declining to initiate removal proceedings, or declining to execute a final order of removal. DACA is one type of deferred action (see the "Deferred Action for Childhood Arrivals" section). DHS has also implemented policies to provide deferred action to workers cooperating in employment and labor standards investigations, certain relatives of U.S. servicemembers and veterans, and crime victims awaiting adjudication of a petition for U nonimmigrant status.¹²³

Footnotes

The Immigration and Nationality Act (INA, P.L. 82-414) is codified, as amended, at 8 U.S.C. §§1101 et seq.

The INA defines "alien" as a person who is not a citizen or a national of the United States. INA §101(a)(3); 8 U.S.C. §1101(a)(3). In this report, the terms alien, foreign national, and noncitizen are synonymous.

Exceptions include citizens or nationals of the (currently) 42 Visa Waiver Program (VWP) designated countries, Canadian USMCA Professional Workers, and citizens of Canada and Bermuda; 8 C.F.R. §212.1. For more information, see CRS Report RL32221, Visa Waiver Program; and DOS, "Travel Without A Visa," https://travel.state.gov/content/travel/en/us-visas/tourism-visit/travel-without-a-visa.html.

Some nonimmigrant visas, including those for H-1B specialty occupation workers, L intracompany transferees, K fiancés, and V accompanying family members allow visa holders to simultaneously seek LPR status.

For more information, see CRS Report R45151, Immigration Consequences of Criminal Activity.

For more information, see CRS In Focus IF11467, Immigration: Public Charge; and CRS Legal Sidebar LSB10341, DHS Final Rule on Public Charge: Overview and Considerations for Congress.

With certain exceptions, persons who depart the United States after being unlawfully present for more than 180 days but less than one year are subject to a 3-year bar on admission; those who depart after being unlawfully present for at least one year are subject to a 10-year bar. INA §212(a)(9)(B); 8 U.S.C. §1182(a)(9)(B).

For more information, see CRS In Focus IF12662, Immigration: Grounds of Inadmissibility.

See INA §222(h), 8 U.S.C. §1202(h) and 22 C.F.R. §41.102 (requirements for nonimmigrant interviews), and 22 C.F.R. §42.62 and DOS, "Immigrant Visa Process," https://travel.state.gov/content/travel/en/us-visas/immigrate/the-immigrant-visa-process/step-10-prepare-for-the-interview/step-11-applicant-interview.html (requirements for immigrant visas).

INA §274C; 8 U.S.C. §1324c.

18 U.S.C. §1546.

In this report, the term admissions broadly refers to the entry of aliens into the United States, either permanently or temporarily. Technically, aliens who immigrate permanently do so either by being admitted as LPRs (if arriving from abroad) or by adjusting status from a temporary status to LPR status (if residing in the United States). For more information on permanent immigration, see CRS Report R42866, Permanent Legal Immigration to the United States: Policy Overview.

In this report, the terms immigrant, lawful permanent resident, and green card-holder are synonymous.

This means that the total number of (numerically limited) family-sponsored preference immigrants and employment-based immigrants from a single country each year is limited by this provision to 7% of the total (226,000 plus 140,000) or 25,620. For more background, see CRS Report R42866, Permanent Legal Immigration to the United States: Policy Overview.

For more information, see CRS Report R42866, Permanent Legal Immigration to the United States: Policy Overview.

USCIS, which processes and adjudicates most immigration-related applications and petitions, operates largely on fee revenue. A fee schedule for all applications and petitions can be found at https://www.uscis.gov/g-1055. For background information, see CRS Report R48021, U.S. Citizenship and Immigration Services (USCIS): Operations and Issues for Congress.

For more information, see CRS In Focus IF12662, Immigration: Grounds of Inadmissibility.

For more information, see DOS, "The Operation of the Immigrant Numerical Control System," https://travel.state.gov/content/dam/visas/Immigrant%20Visa%20Control%20System_operation%20of.pdf.

When the demand for such visas exceeds 226,000, the 226,000 limit also acts as a floor, below which the number of family preference immigrants cannot fall. More than 226,000 family preference immigrants can be admitted under current law only if the number of immediate relatives admitted, less the number of any unused employment-based preference numbers from the prior year as well as any immigrant visas issued to several other relatively minor groups, is fewer than 254,000 (the difference between 480,000 and 226,000). However, annual admissions of immediate relatives less unused employment-based preference numbers from the prior year have exceeded 254,000 every year since 2001. For instance, in FY2023 immediate relatives totaled 551,590. Under these statutory constraints, family-sponsored preference category immigrants are effectively limited to 226,000 per year.

For more information, see CRS Report R43145, U.S. Family-Based Immigration Policy.

For a complete list of special immigrant categories, see USCIS, "Employment-Based Immigration: Fourth Preference EB-4," at https://www.uscis.gov/working-in-the-united-states/permanent-workers/employment-based-immigration-fourth-preference-eb-4.

The EB-5 visa was created through the Immigration Act of 1990 (P.L. 101-649). For more background, see CRS Report R44475, EB-5 Immigrant Investor Program.

For more information, see CRS Report R42866, Permanent Legal Immigration to the United States: Policy Overview.

INA §203(c); 8 U.S.C. §1153(c). For more information about diversity visas, see CRS Report R45973, The Diversity Immigrant Visa Program.

See archived CRS Report R45102, Diversity Immigrants' Regions and Countries of Origin: Fact Sheet and DHS Office of Homeland Security Statistics, 2023 Yearbook of Immigration Statistics.

Such individuals may register for the lottery again in subsequent years.

INA §101(a)(42); 8 U.S.C. §1101(a)(42). While persons seeking refugee status often reside in a second country that is neither their home country nor the United States, some reside in their home countries in certain circumstances. See §101(a)(42)(B); 8 U.S.C. §1101(a)(42)(B).

For more information about refugee admissions, see CRS Report R47399, U.S. Refugee Admissions Program.

For annual refugee ceilings and admissions from FY1981 through FY2022, see Appendix A in CRS Report R47399, U.S. Refugee Admissions Program.

The White House, "Presidential Determination on Refugee Admissions for Fiscal Year 2021," 85 Federal Register 71219-71221, November 6, 2020. In May 2021, President Biden issued an emergency presidential determination to raise the FY2021 refugee ceiling to 62,500. See The White House, "Memorandum for the Secretary of State on the Emergency Presidential Determination on Refugee Admissions for Fiscal Year 2021," May 3, 2021.

The White House, "Presidential Determination on Refugee Admissions for Fiscal Year 2025," 89 Federal Register 83767, September 30, 2024.

DOS, Bureau of Population, Refugees, and Migration, "Summary of Refugee Admissions as of October 31, 2024," https://www.wrapsnet.org/admissions-and-arrivals/.

INA §209(a); 8 U.S.C. §1159(a).

INA §208(a)(1); 8 U.S.C. §1158(a)(1).

INA §208; 8 U.S.C. §1158. For information on statutory bars on applying for asylum, see CRS Legal Sidebar LSB10815, An Overview of the Statutory Bars to Asylum: Limitations on Applying for Asylum (Part One).

For more information about affirmative asylum, see CRS Report R48249, What Is Affirmative Asylum?.

For more information about defensive asylum, see CRS Report R47504, Asylum Process in Immigration Courts and Selected Trends.

INA §209(b); 8 U.S.C. §1159(b).

For a detailed and complete list of categories of foreign nationals receiving LPR status, see DHS, Office of Homeland Security Statistics, 2023 Yearbook of Immigration Statistics, Table 7.

INA §240A; 8 U.S.C. §1229b.

INA §240A(e); 8 U.S.C. §1229b(e).

INA §101(a)(15)(U); 8 U.S.C. §1101(a)(15)(U).

INA §214(p)(2); 8 U.S.C. §1184(p)(2). There is no limit for family members who derive U status or T status from the principal applicant, such as spouses, children, or other eligible family members. For more information, see CRS Report R47404, Immigration Relief for Noncitizen Crime Victims.

INA §101(a)(15)(T); 8 U.S.C. §1101(a)(15)(T). For more information, see CRS Report R46584, Immigration Relief for Victims of Trafficking and CRS Report R47404, Immigration Relief for Noncitizen Crime Victims.

Exceptions may be granted to individuals who are unable to cooperate with a request for assistance due to physical or psychological trauma or because they are under age 18. INA §101(a)(15)(T)(i)(III); 8 U.S.C. §1101 (a)(15)(T)(i)(III).

INA §214(o)(2), 8 U.S.C. §1184(o)(2); INA §245(l)(4)(A), 8 U.S.C. §1255(l)(4)(A).

INA §316; 8 U.S.C. §1427. For more information, see CRS Report R43366, U.S. Naturalization Policy and CRS In Focus IF12322, Naturalization: Policy Overview and Selected Trends.

The INA contains provisions for expedited naturalization through qualifying military service, INA §§328, 329; 8 U.S.C. §§1439, 1440. For more information, see CRS Report R48163, Foreign Nationals in the U.S. Armed Forces: Immigration Issues.

INA §319; 8 U.S.C. §1429.

USCIS, "Naturalization Statistics," https://www.uscis.gov/citizenship-resource-center/naturalization-statistics, January 24, 2025.

U.S. Census Bureau, 2023 American Community Survey data, 1-year estimates.

Sarah Miller, Estimates of the Lawful Permanent Resident Population in the United States and the Subpopulation Eligible to Naturalize: 2024 and Revised 2023, DHS Office of Homeland Security Statistics, September 2024.

INA §340(a); 8 U.S.C. §1451(a).

INA §101(a)(15); 8 U.S.C. §1101(a)(15).

For more information, see CRS Report R45040, Immigration: Nonimmigrant (Temporary) Admissions to the United States.

INA §214(b); 8 U.S.C. §1184(b). Many temporary visa holders eventually are able to adjust their status to LPR status after they have been admitted to the United States as nonimmigrants. In FY2023, for example, of the 1,172,910 foreign nationals who were granted LPR status, 564,660 (48%) were new arrivals from abroad and 608,260 (52%) adjusted status from a nonimmigrant status while residing in the United States. Data to show the nonimmigrant categories that foreign nationals adjust status from are unavailable. See DHS 2023 Yearbook of Immigration Statistics, Table 6.

For a list of nonimmigrant categories and annual numerical limits, see CRS Report R45938, Nonimmigrant and Immigrant Visa Categories: Data Brief.

See CRS Report R45938, Nonimmigrant and Immigrant Visa Categories: Data Brief and DOS, Bureau of Consular Affairs, Report of the Visa Office 2023.

8 C.F.R. §212.6

DOS, Bureau of Consular Affairs, Report of the Visa Office 2023, Table XVI.

8 C.F.R. §235.1.

For more information, see CRS Report RL32221, Visa Waiver Program.

See DHS Office of Homeland Security Statistics, 2023 Yearbook of Immigration Statistics, Table 25.

For more information, see CRS Report R47848, Nonimmigrant Overstays: Overview and Policy Issues.

INA §244, 8 U.S.C. §1254a. For more information, see CRS Report RS20844, Temporary Protected Status and Deferred Enforced Departure.

For more information, see CRS Report RS20844, Temporary Protected Status and Deferred Enforced Departure.

For more information, see CRS Report RS20844, Temporary Protected Status and Deferred Enforced Departure.

INA §212(d)(5); 8 U.S.C. §1182(d)(5).

Cubans are an exception because Congress established a special pathway to LPR status for Cuban parolees under the Cuban Adjustment Act of 1966 (P.L. 89-732).

For more information, see CRS Report R46570, Immigration Parole.

See, for example, DHS, "Termination of Parole Processes for Cubans, Haitians, Nicaraguans, and Venezuelans," 90 Federal Register 56, March 25, 2025. For more information on Biden Adminstration-era special parole processes, see CRS Report R47654, Immigration Options for Immigration Parolees; for information on legal debates and changes under the second Trump Administration, see CRS Legal Sidebar LSB11102, Humanitarian Parole Authority: A Legal Overview and Recent Developments and CRS Legal Sidebar LSB11265, Recent White House Actions on Immigration.

For more information, see CRS Report R46764, Deferred Action for Childhood Arrivals (DACA): By the Numbers.

USCIS, "Glossary," https://www.uscis.gov/tools/glossary.

At that time, DACA recipients' average age was 30.6. USCIS, "Count of Active DACA Recipients as of September 30, 2024," available from USCIS, "Immigration and Citizenship Data," https://www.uscis.gov/tools/reports-and-studies/immigration-and-citizenship-data.

For more information, see CRS Legal Sidebar LSB10625, The Legality of DACA: Recent Litigation Developments.

USCIS, "Consideration of Deferred Action for Childhood Arrivals," https://www.uscis.gov/DACA, January 24, 2025.

This report does not cover immigration enforcement along U.S. coastal waters, which the U.S. Coast Guard, Alien Migrant Interdiction Operations oversees. For more information, see DHS, Office of Homeland Security Statistics, U.S. Coast Guard Maritime Response Activities Fiscal Year 2020-2023.

U.S. Government Accountability Office (GAO), U.S. Customs and Border Protection: Efforts to Improve Recruitment, Hiring, and Retention of Law Enforcement Personnel, GAO-24-107029, September 2024.

For more information, see CRS Report R46783, Trusted Traveler Programs.

INA §221(h); 8 U.S.C. §1201(h).

This requirement was enacted in the Illegal Immigration Reform and Immigrant Responsibility Act of 1996 (IIRIRA, P.L. 104-208), Section 110.

Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act (USA PATRIOT Act, P.L. 107-56), Section 414.

For more information, see CRS Report R47541, Immigration: The U.S. Entry-Exit System.

For more information, see CRS Report R47541, Immigration: The U.S. Entry-Exit System.

USBP, 2024-2028 Strategy, March 2024.

For example, in March 2025 CBP announced plans to complete seven miles of new border wall in the USBP's Rio Grande Valley Sector with FY2021 funds. CBP, "CBP awards first border wall contract of President Trump's second term," March 15, 2025.

See archived CRS Insight IN11040, Border Security Between Ports of Entry: Homeland Security Issues in the 116th Congress.

GAO, U.S. Customs and Border Protection: Efforts to Improve Recruitment, Hiring, and Retention of Law Enforcement Personnel, GAO-24-107029, September 2024.

Among all CBP encounters at the Southwest border, the proportion with children and family units was 41% in FY2025 through February, 43% in FY2024, 39% in FY2023, and 30% in FY2022. CBP, "Nationwide Encounters," https://www.cbp.gov/newsroom/stats/nationwide-encounters. See also Figure 2 in archived CRS Report R47556, U.S. Border Patrol Encounters at the Southwest Border: Fact Sheet.

CBP, "Nationwide Encounters," https://www.cbp.gov/newsroom/stats/nationwide-encounters.

Unaccompanied alien children are children who are under age 18, lack lawful immigration status in the United States, and do not have a parent or legal guardian in the United States, or a parent or legal guardian who is available to provide care and physical custody. For more information, see CRS Report R43599, Unaccompanied Alien Children: An Overview.

For more information, see CRS Legal Sidebar LSB10578, The Biden Administration's Immigration Enforcement Priorities: Background and Legal Considerations and CRS Legal Sidebar LSB10362, Immigration Arrests in the Interior of the United States: A Primer.

The program has also been referred to as the Criminal Apprehension Program. An ICE website, https://www.ice.gov/identify-and-arrest/criminal-alien-program, updated January 27, 2025, refers to this program as the Criminal Alien Program; its FY2024 annual report uses Criminal Apprehension Program; ICE, ICE Annual Report FY2024, p. 93.

ICE, ICE Annual Report FY2024, p. 15.

For background information, see CRS In Focus IF11898, The 287(g) Program: State and Local Immigration Enforcement.

INA §274A; 8 U.S.C. §1324a.

This material is adapted from CRS In Focus IF11343, The Law of Immigration Detention: A Brief Introduction. For more information on standards and criteria for making detention decisions, see also CRS Report R45915, Immigration Detention: A Legal Overview.

This number includes facilities owned and operated by ICE, a state or local entity, or a contractor and excludes "hold rooms, hospital, and juvenile facilities." ICE, Annual Report Fiscal Year 2024, p. 22. See also ICE, "Detention Management," https://www.ice.gov/detain/detention-management.

ICE, Annual Report Fiscal Year 2024, p. 23.

See ICE, Annual Report Fiscal Year 2024, p. 22 and CRS Report R45915, Immigration Detention: A Legal Overview.

ICE, Annual Report Fiscal Year 2024, p. 27.

See ICE, "Alternatives to Detention," https://www.ice.gov/features/atd.

ICE, Annual Report Fiscal Year 2024, p. 29.

Grounds of inadmissibility are outlined in INA Section 212; 8 U.S.C. §1182. If individuals are removed because they were inadmissible at the time of entry, they are removed under INA Section 212, not INA Section 237. For more information, see CRS In Focus IF12662, Immigration: Grounds of Inadmissibility.

Crimes of moral turpitude are determined by case law. For more information, see CRS Report R45151, Immigration Consequences of Criminal Activity.

INA §239; 8 U.S.C. §1229. For more information on immigration courts, see CRS Report R47077, U.S. Immigration Courts and the Pending Cases Backlog.

INA §240; 8 U.S.C. §1229a. For more information about formal removal proceedings, see CRS In Focus IF11536, Formal Removal Proceedings: An Introduction.

For more information about reinstatement of removal, see CRS In Focus IF11736, Reinstatement of Removal Orders: An Introduction.

INA §235(b)(1); 8 U.S.C. §1225. For more information about expedited removal, see CRS In Focus IF11357, Expedited Removal of Aliens: An Introduction.

For more information, see CRS Report R48078, Credible Fear and Defensive Asylum Processes: Frequently Asked Questions.

INA §241(a); 8 U.S.C. §1231(a).

For more information, see CRS Report R45915, Immigration Detention: A Legal Overview.

For more information, see CRS In Focus IF11025, Immigration: "Recalcitrant" Countries and the Use of Visa Sanctions to Encourage Cooperation with Alien Removals.

INA §212(a)(9)(A); 8 U.S.C. §1182(a)(9)(A). For more information, see CRS In Focus IF12484, The Statutory Bars to Reentry into the United States.

If an individual is subject to removal but has not been placed in removal proceedings, they may apply for affirmative asylum.

For more information, see CRS Report R48078, Credible Fear and Defensive Asylum Processes: Frequently Asked Questions.

INA §241(b)(3)(A); 8 U.S.C. §1231(b)(3)(A), INS v. Stevic, 467 U.S. 407, 424, 429 ̶ 30 (1984) (explaining that an application for withholding of removal must "be supported by evidence establishing that it is more likely than not that the alien would be subject to persecution on one of the specified grounds."). For more information, see CRS Report R48078, Credible Fear and Defensive Asylum Processes: Frequently Asked Questions.

See archived CRS Report RL32276, The U.N. Convention Against Torture: Overview of U.S. Implementation Policy Concerning the Removal of Aliens (available to congressional clients upon request to CRS).

For more information, see "Asylum and Related Forms of Relief" in CRS Report R48078, Credible Fear and Defensive Asylum Processes: Frequently Asked Questions.

According to DHS, "Although deferred action does not confer lawful status or excuse any past or future periods of unlawful presence, a noncitizen granted deferred action is considered lawfully present in the United States for certain limited purposes, while the deferred action is in effect." DHS, "DHS Support of the Enforcement of Labor and Employment Laws," January 6, 2025.

See USCIS, "DHS Support of the Enforcement of Labor and Employment Laws," last updated January 24, 2025.