Primer on U.S. Immigration Policy July 1, 2021 U.S. immigration policy is governed largely by the Immigration and Nationality Act (INA), which was first codified in 1952 and has been amended significantly several times since. At a fundamental level, U.S. immigration policy can be viewed as two sides of a coin. One side emphasizes the faciliation ofU.S. William A. Kandel immigration policy contains two major aspects. One facilitates migration flows into the United Analyst in Immigration States according to principles of admission that are based upon national interest. These broad Policy principles currently include family reunification, U.S. labor market contribution, humanitarian assistance, and origin-country diversity.

origin-country diversity, and humanitarian assistance. The United States has long distinguished permanent immigration from temporary migrationimmigration. Permanent immigration occurs through family and employer-sponsored categories, the diversity immigrant visa lottery, and refugee and asylee admissions. Temporary migrationimmigration occurs through the admission of visitorsforeign nationals for specific purposes and limited periods of time, and encompasses two dozen categories of visitors, including that include foreign tourists, students, temporary workers, and diplomats.

The other side of the immigration policy coin emphasizes the restriction of entry to and removal of The other major aspect of U.S. immigration policy involves restricting entry to and removing persons from the United States who lack authorization to residebe in the country, are identified as criminal aliens, or whose presence in the United States is not considered to be indetermined to not serve the national interest. Such immigration enforcement is broadly divided between border enforcement—at and between U.S. land, air, and sea ports of entry—and other enforcement tasks including interior enforcement, detention, removal, worksite enforcement, and combatting immigration fraud.

The dual role of U.S. immigration policy —admissions and enforcement—creates challenges for balancing major policy priorities, such as ensuring national security, facilitating trade and commerce, protecting public safety, and fostering international cooperation.

This report provides a broad overview of U.S. immigration policy. The first section addresses policies governing how foreign nationals enter the United States either to to either reside permanently or to stay temporarily. Related topics within this section include visa issuance and security, forms of quasi-legal status, and naturalization. The second section discusses enforcement policies both for excluding foreign nationals from admission into the United States, as well wel as for detaining and removing those who enter the country unlawfully or who enter lawfully but subsequently commit crimes that make them deportable. The section also covers worksite enforcement and immigration fraud. The third section of this report addresses policies for unauthorized aliensaliens1 residing in the United States. While intended to be comprehensive, this primer may omit some immigration-related topics. ItFor example, it general y does not discuss policy issues or congressional concerns about specific immigration-related policies and programs.

Immigration Inflows and Related Topics

U.S. immigration policy is governed largely by the Immigration and Nationality Act (INA), which was first codified in 1952 and has been amended significantly several times since.¹ 2 Implementation of INA policies is carried out by multiple executive branch agencies. The Department of Homeland Security (DHS) has primary responsibility for immigration functions through several agencies: U.S. Citizenship and Immigration Services (USCIS), U.S. Customs and Border Protection (CBP), and U.S. Immigration and Customs Enforcement (ICE). The Department of State (DOS) issues visas to foreign nationals overseas, and the Department of Justice (DOJ) operates immigration courts through its Executive Office offor Immigration Review (EOIR).

Foreign-born populations with different legal statuses are referred to throughout this report. The term aliens The Department of Labor (DOL) operates a foreign labor certification program to ensure that foreign workers do not displace or adversely affect working conditions of U.S. workers. This report uses specific terms to refer to foreign-born populations having different legal statuses. The legal term aliens refers to people who are not U.S. citizens, including those legally and not legally present.² The two basic types of legal aliensboth legal y and not legal y present. The two main types of aliens lawfully present in the United States are (1) immigrants (not includingthis term excludes refugees and asylees) and (2) nonimmigrants. ImmigrantsImmigrants refers to foreign nationals lawfully admitted to the United States for permanent residence.³ Nonimmigrants3 Nonimmigrants refers to foreign nationals temporarily and lawfullylawfully and temporarily admitted to the United States for a specificspecified purpose and period of time, including tourists, diplomats, students, temporary workers, and exchange visitors, among others.

Refugees and asylees refer to persons fleeing their countries because of persecution, or a well The terms refugees and asylees identify individuals who are not formal y classified as immigrants under the INA and refer to persons who are outside of their home countries and unable or unwil ing to return because of persecution, or a wel -founded fear of persecution, on account of race, religion, nationality, membership in a particular social group, or political opinion (see "“Refugees and Asylees”).4 Once admitted, refugees and asylees may apply to adjustRefugees and Asylees"). Refugees and asylees are not classified as immigrants under the INA, but once admitted, they may adjust their status to lawful to lawful permanent resident (LPR).

Naturalized status. Naturalized citizens refers to LPRs who become U.S. citizens through a process known as naturalization (described below), generallygeneral y after residing in the United States continuously for at 1 T he INA defines alien as a person who is not a citizen or a national of the United States. See INA §101(a)(3). In this report, the terms alien, foreign national, and noncitizen are synonymous. 2 T he INA (P.L. 82-414) is Act of June 27, 1952, ch. 477, codified, as amended, at 8 U.S.C. §§1101 et seq. 3 In this report, the terms immigrant, lawful permanent resident (LPR), and green card-holder are synonymous. 4 INA §101(a)(42), 8 U.S.C. §1101(a)(42). Congressional Research Service 1 link to page 8 Primer on U.S. Immigration Policy after residing in the United States continuously for at least five years. NoncitizensNoncitizens are persons who have not naturalized and may include immigrants as well as nonimmigrants.

Unauthorized aliens wel as nonimmigrants. Unauthorized aliens refers to foreign nationals who reside unlawfully in the United States and who . They either entered the United States illegally ("il egal y (without inspection") or entered lawfully and temporarily ("(with inspection") but subsequently violated the terms of their admission, typically by "overstaying" typical y by overstaying their visa duration.⁴

5 Permanent Immigration⁵

Immigration6 Four general principles underlie the current system of permanent immigration: family reunification, U.S. labor market contribution, origin-country diversity, and humanitarian assistance. These principles are reflected in different components of permanent immigration. Family reunification occurs primarily through family-sponsored immigration. U.S. labor market contribution occurs through employment-based immigration. Origin-country diversity is addressed through the Diversity Immigrant Visa. Humanitarian assistance occurs primarily through the U.S. refugee and asylee programs. These permanent immigration pathways are discussed further below.

The INA limits worldwide permanent immigration to 675,000 persons annuallyannual y: 480,000 family-sponsored immigrants, made up of family-sponsored immediate relatives of U.S. citizens ("immediate relatives"), and a set of ordered family-sponsored preference immigrants ("preference immigrants"); 140,000 employment-based employment-based immigrants; and 55,000 diversity visa immigrants.⁶7 This worldwide limit, however, is referred to as a "permeable cap" because immediate relatives are exempt from numerical limits placed on family-sponsored immigration (described below) and thereby represent the flexible component of the 675,000 worldwide limit. In addition, the annual number of refugees is determined not by statute but by the President, in consultation with Congress.⁷ Asylees are adjudicated on a case-by- case basis without a statutorily mandated limit (see “Refugees and Asylees”). Consequently, actual total annual LPRs (immigrants, refugees, and asylees) have averaged roughly 1 million persons during the past decade.

To ensure thatexceeded 1 mil ion persons in al but 4 of the past 20 years. To ensure that foreign nationals from only a few countries do not dominate permanent immigration flows, the INA further specifies a "7% per-country limit" or "cap" limiting on the number of family- sponsored preference immigrants and all employment-based immigrants from anya single country.8 5 Also counted in this population are persons with parole or other forms of quasi-legal status (described below). 6 In this report, the term admissions broadly refers to the entry of aliens into the United States, either permanently or temporarily. T echnically, aliens who immigrate permanently do so either by being adm itted as LPRs (if arriving from abroad) or by adjusting status from a temporary nonimmigrant status to LPR status (if residing in the United States). For more information on permanent immigration, see CRS Report R42866, Perm anent Legal Im migration to the United States: Policy Overview. 7 See, respectively, INA §201(c), INA §201(d), and INA §201(e). While the diversity visa category has not been directly amended since its enactment, the Nicaraguan Adjustment and Central American Relief Act of 1997 (NACARA; P.L. 105-100) temporarily reduced the 55,000 annual ceiling beginning in FY1999 by up to 5,000 annually to offset immigrant numbers made available to certain unsuccessful asylum seekers from El Salvador, Gua temala, and formerly communist countries in Europe. T he 5,000 offset is nearing an end; for FY2021, the reduction was limited to approximately 150. 8 For more background, see CRS Report R42866, Permanent Legal Immigration to the United States: Policy Overview. Congressional Research Service 2 link to page 6 link to page 7 Primer on U.S. Immigration Policy single country to 7% of the limit in each preference category.⁸

Family-Sponsored Immigration

Family-sponsored immigration consists of two immigrant groups (Table 1). Immediate relativesImmediate relatives include spouses and minor unmarried children of U.S. citizens and parents of adult U.S. citizens. An unlimited number of immediate relativesImmediate relatives are not subject to annual numerical limits and can acquire LPR status each year if they meet the standard eligibility criteria required of all al immigrants. PreferencePreference immigrants, on the other hand, are numericallynumerical y limited to 226,000 per year and, unlike immediate relatives, are also bounded by the 7% per-country limit.⁹9 In recent years, family-sponsored immigrants have accounted for roughly two-thirds of al persons receiving LPR status.10 Table 1. Family-Sponsored Immigrant Categories Category Individuals two-thirds of all permanent immigration.¹⁰

Note: LPR = lawful permanent resident. Employment-Based Immigration

Employment-based immigration occurs through five numericallynumerical y limited preference categories (Table 2), the first three of which are ranked bybased on professional accomplishment and ability. The fourth preference category includes various "“special immigrants.”11 The fifth preference category is for immigrant investorsspecial immigrants,"¹¹ and the fifth preference category includes immigrant investors (i.e., EB-5 visa holders), a category created in 1990 to benefit the U.S. economy through employment creation and capital investment.¹²12 Employment-based immigrants also include accompanying spouses and children of qualifying LPRs,; are limited to 140,000 total annual admissions, and are subject to the same 7% per-country limit; and are 9 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, 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 FY2019 (the most recent year for which data are available), immediate relatives totaled 505,765. T hus, under these statutory constraints, family-sponsored preference category immigrants are effectively limited to 226,000 per year. 10 For more background, see CRS Report R43145, U.S. Family-Based Immigration Policy. 11 For a complete list of special immigrant categories, see USCIS, “Special Immigrants,” at https://www.uscis.gov/humanitarian/special-immigrants. 12 T he EB-5 visa was created through the Immigration Act of 1990 (P.L. 101-649). For more background, see CRS Report R44475, EB-5 Im m igrant Investor Visa. Congressional Research Service 3 link to page 12 Primer on U.S. Immigration Policy subject to the same 7% per-country limit for each preference category as family-sponsored as family-sponsored preference immigrants.¹³

Visa Queue

When a visa becomes available, it allows an approved prospective immigrant to travel to the an approved prospective immigrant to travel to the United States and, if admitted to the country by an immigration officer at a port of entry, receive LPR status. If the approved prospective immigrant already resides in the United States on a nonimmigrant visa, the availability of a visa allows him or her to "adjust status" (i.e., change from(in this case, an LPR slot) al ows him/her to adjust status. Adjusting status permits a temporary nonimmigrant to become a permanent immigrant with LPR status) without having to return to thehis/her country of origin to complete visa processing through a DOS consulate. 13 For more information, see CRS Report R42866, Permanent Legal Immigration to the United States: Policy Overview. 14 For more information, see CRS Report R42866, Permanent Legal Immigration to the United States: Policy Overview. Congressional Research Service 4 Primer on U.S. Immigration Policy Visa Queue The number of foreign nationals seeking to immigrate to the United States each year through family-sponsored and employment-based preference categories typical y exceeds the INA-mandated numerical limits. The 7% per-country cap primarily affects foreign nationals from countries that send relatively large numbers of immigrants to the United States (e.g., Mexico, China, India, Philippines). As a result, many foreign nationals who meet the U.S. immigrant qualifications, and whose immigrant petitions USCIS has approved, must wait years before a numerical y limited visa (or LPR slot) from DOS becomes available. consulate. As of November 1, 2017, 2020, the queue of approved family-sponsored and employment-basedimmigrants waiting for LPR status numbered 3.8 mil ion persons.15 As of November 16, 2020, the queue of approved employment-sponsored immigrants waiting for LPR status numbered roughly 1 mil ion persons.16 immigrants waiting for visas numbered 4.1 million persons.¹⁴

Diversity Immigrant Visa

The diversity immigrant visa fosters legal immigration from countries that send relatively few immigrants to the United States.¹⁵17 Each year, 5055,000 visas are made available to selected natives of countries from which immigrant admissions totaled less than 50,000 over the preceding five years. Since the visa'’s inception in the early 1990s, the regional distribution of diversity lottery immigrants has shifted from Western European to African and Eastern European countries.¹⁶

18 To be eligible for a diversity immigrant visa, foreign nationals must have a high school education or two years of work experience within the past five years in an occupation that requires at least two years of training or experience to perform. Diversity immigrant visa applicants are selected by lottery. Winners ofThose selected from the diversity immigrant visa lottery must also meet the standard eligibility eligibility criteria required for most immigrants.

before they are al owed entry into the United States. Refugees and Asylees

The United States has long held to the principle that it will wil not return a foreign national to a country where his or /her life or freedom would be threatened. This is embodied in several INA provisions, notably in those defining refugees and asylees. A refugee is a person who is outside his or her home country (a second country that is not the United States) and is unable or unwilling to returnunable or unwil ing to return to their home country or country of residence because of persecution, or a wellwel -founded fear of persecution, on account of five possible criteria: (1) race, (2) religion, (3) nationality, (4) membership in a particular social group, or (5) political opinion.19 An asylee is a person who meets the definition of a refugee in terms of persecution or a wellwel -founded fear of persecution but who has been admittedis present in the United States or is present at a land border or port of entry to the United States.

15 U.S. Department of State, National Visa Center, Annual Report of Immigrant Visa Applicants in the Family-sponsored and Em ploym ent-based preferences Registered at the National Visa Center as of Novem ber 1, 20 20. For more discussion of the visa queue, see CRS Report R43145, U.S. Fam ily-Based Im migration Policy. 16 U.S. Citizenship and Immigration Services, “ Form I 140, I 360, I 526 Approved Employment Based Petitions Awaiting Visa Availability by Preference Category and Country of Birth As of November 16, 2020.” For background information on how this queue is computed, see archived CRS Report R45447, Perm anent Em ployment-Based Im m igration and the Per-country Ceiling. 17 For more information, see CRS Report R45973, The Diversity Immigrant Visa Program . 18 For more information, see CRS Report R45102, Diversity Immigrants’ Regions and Countries of Origin: Fact Sheet. 19 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 8 U.S.C. §1101)(a)(42)(B). Congressional Research Service 5 link to page 19 Primer on U.S. Immigration Policy Refugee status is granted within numerical limits. Refugee admissions differ from other immigrant admissions because their annual number, known as the refugee ceiling, and their allocation by world region al ocation are not mandated in statute but set each year by the President, in consultation with Congress. Between FY2000 and FY2019, the annual refugee ceiling number of U.S. refugees admitted averaged 55,934, with a low of 22,544 (in FY2018) and a high of 84,994 (in FY2016).20 The variation in refugee admissions is largely due to variation in the refugee ceilings set during this time. Annual refugee admissions are typical y lower than permitted by the annual refugee ceiling because of delays from processing and screening. For FY2021Congress. For FY2018, the worldwide refugee ceiling was set at 45,000, allocated among world regions (Africa, East Asia15,000, the lowest in the 40-year history of the U.S. Refugee Admissions Program. In contrast with prior years’ regional al ocations, refugee al ocations in FY2021 were made by “population of special humanitarian concern.” These populations included refugees facing persecution on religious grounds (5,000); refugees from Iraq (4,000); refugees from El Salvador, Guatemala, or Honduras (1,000); and refugees in other specified groups (5,000).21 In 2021, the Biden Administration issued two emergency determinations that changed the al ocation process back to a regional al ocation and increased the FY2021 refugee ceiling to 62,500. The regional al ocations are as follows: Africa (22,000), East Asia (6,000), Europe and Central Asia (4,000), Latin America and the Caribbean (5,000), Near East and South Asia (13,000), and an unal ocated reserve (12,500).22 Asylum is not numerical y limited. A foreign national in the United States may affirmatively apply to USCIS for asylum or may defensivelyCentral Asia, Latin America/Caribbean, and Near East/South Asia).¹⁷

Asylum is granted on a case-by-case basis and is not numerically limited. An alien in the United States may "affirmatively" apply to USCIS for asylum or may "defensively" seek asylum before an immigration judge during proceedings that determine an individual'’s removability under the INA.¹⁸ Typically, aliens23 Typical y, foreign nationals arriving at a U.S. port of entry who lack proper immigration documents for admission or who engage in fraud or misrepresentation are placed in expedited removal (described below); howeversee “Removal”). However, if they express a fear of persecution, they receive a "credible fear" review by a USCIS asylum officer and—if found to have credible fear—are placed in standard removal proceedings and referred to an immigration judge for a hearing.¹⁹

on their asylum claims.24 Other Pathways to Lawful Permanent Resident Status

In addition to the primary components of permanent immigration discussed above, there arethe INA contains several other pathways to LPR status, though they account for relatively few immigrants each year. The most prominent among these are cancellation of removal, U nonimmigrant visas, and T status.²⁰

Cancellation of removal is a discretionary, case-by-casecancellation of removal, U nonimmigrant visas, and T nonimmigrant status.25 20 See U.S. Department of State, Bureau of Population, Refugees and Migration, Office of Admissions – Refugee Processing Center, “ Summary of Refugee Admissions as of 30-April-2021.” For additional information, see CRS Report RL31269, Refugee Adm issions and Resettlem ent Policy. 21 T he White House, “Presidential Determination on Refugee Admissions for Fiscal Year 2021,” 85 Federal Register 71219-71221, November 6, 2020. According to DOS’s Refugee Processing Center, 11,814 refugees were admitted in FY2020, and 2,334 have been admitted in FY2021 as of April 30, 2021. Ibid. 22 Executive Office of the President, “Emergency Presidential Determination on Refugee Admissions for Fiscal Year 2021,” 86 Federal Register 21159-21160, April 22, 2021; and Executive Office of the President, “Emergency Presidential Determination on Refugee Admissions for Fiscal Year 2021,” 86 Federal Register 24475-24476, May 7, 2021. 23 For more information, see CRS Report R45539, Immigration: U.S. Asylum Policy. 24 INA §235(b) defines credible fear as a significant possibility, taking into account the credibility of the statements made by the alien and other facts known to the officer, that the alien could establish eligibility for asylum. 25 For a detailed and complete list of categories of foreign nat ionals receiving LPR status, see DHS Office of Congressional Research Service 6 link to page 12 Primer on U.S. Immigration Policy Cancellation of removal is a discretionary form of relief granted by an immigration judge to aliens in removal proceedings. To receive it, an aliena foreign national must demonstrate substantial ties to the United States, be of good moral character, and not have been convicted of a crime that makes him or /her removable. More specific requirementsRequirements differ by legal status.²¹, with nonpermanent residents facing more stringent requisites than permanent residents.26 Because an immigration judge grants cancellationcancel ation of removal at his or /her discretion, no fixed standard exists for who merits relief. The alien foreign national must show that he or /she is eligible for and deserves the relief. Grants of cancellation cancel ation of removal are limited to 4,000 LPRs and 4,000 nonpermanent residents per year.²²

27 U nonimmigrant visas are granted to certain victims who help law enforcement agencies investigate and prosecute domestic violence, sexual assault, human trafficking, and other crimes. After meeting specific requirements, U visa recipients, as well as To qualify for U status, a foreign national must file a petition and establish that he/she (1) suffered substantial physical or mental abuse as a result of having been a victim of qualifying crimes that violated the laws of the United States or occurred in the United States; (2) possesses information about the criminal activity involved as certified by a law enforcement or immigration official; and (3) has been, is being, or is likely to be helpful in the investigation and prosecution of the crime(s) by federal, state, or local law enforcement authorities. U visa recipients, as wel as their immediate family members, can acquire LPR status. The INA limits U visas to 10,000 per year.

T principal applicants annual y.28 T nonimmigrant status is granted to alien victims of severe forms of human trafficking.²³29 T status recipients may remain in the United States for four years and apply for LPR status after three. To qualify for T status, trafficking victims must also (1) be physically(1) demonstrate that they are victims of a severe form of trafficking in persons; (2) be physical y present in the United States, its territories, or a U.S. port of entry either because of such trafficking or to because they wil participate in related investigations or prosecutions; (23) have complied with requests to assist law enforcement investigating or prosecuting trafficking acts; and (34) be likely to suffer unusual and severe harm upon removal. Such aliens must also be admissible to the United States or obtain a waiver of inadmissibilityinadmissibility (see “Visa Issuance and Security”). The INA limits T status to 5,000 principal applicants annual y. Temporary Immigration Each year, the United States admits mil ions of nonimmigrants, such as tourists, foreign students, diplomats, temporary workers, exchange visitors, international y known entertainers, intracompany business personnel, and crew members on foreign vessels. DOS issues specific types of nonimmigrant visas within 24 major nonimmigrant visa categories. Categories are often referred to by the letter and numeral denoting the related subsection within INA Section 101(a) (e.g., B-2 tourists, F-1 foreign students, H-2A temporary agricultural workers).30 Immigration Statistics, 2019 Yearbook of Im m igration Statistics, T able 7. 26 For example, nonimmigrants and unauthorized aliens who seek cancelation of removal must establish that removal would result in “exceptional and extremely unusual hardship” to the alien’s citizen or LPR spouse, parent, or child. T hat same standard does not apply to immigrants (LPRs). 27 For more information, see CRS Report R43892, Alien Removals and Returns: Overview and Trends. 28 T here 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 R46584, Im migration Relief for Victim s of Trafficking. 29 For more information, see CRS Report R46584, Immigration Relief for Victims of Trafficking. 30 For more information, see CRS Report R45040, Immigration: Nonimmigrant (Temporary) Admissions to the United Congressional Research Service 7 link to page 12 Primer on U.S. Immigration Policy Requirements for Temporary Admission . The INA limits T status to 5,000 principal aliens annually.

Requirements for Permanent Admissions

Temporary Admissions

Each year, the United States admits millions of nonimmigrants, including tourists, foreign students, diplomats, temporary workers, exchange visitors, internationally known entertainers, foreign media representatives, intracompany business personnel, and crew members on foreign vessels. DOS issues 87 specific types of nonimmigrant visas within 24 major nonimmigrant visa categories. Categories are often referred to by the letter and numeral denoting their subsection within INA Section 101(a) (e.g., B-2 tourists, E-2 treaty investors, F-1 foreign students).

Requirements for Temporary Admission

Foreign nationals who apply for temporary admission must demonstrate, both to DOS consular officers at the time they apply for a visa in their home countries, as well wel as to CBP officers when they apply for admission upon arrival in the United States, that they are eligible for both nonimmigrant status general y and the specific requested nonimmigrant visa. In addition, because the INA presumes that all al aliens seeking admission to the United States are coming to live permanently, nonimmigrant applicants must demonstrate that they intend to stay for a temporary period and a specific purpose.²⁵ (see “Visa Issuance and Security”).31 With certain exceptions, nonimmigrants are prohibited from working in the United States.²⁶

In recent years, the most numerous nonimmigrantslargest nonimmigrant groups entering the United States have included B-1 business visitors; and B-2 tourists; (temporary visitors for business or pleasure), Border Crossing Card holders;, L intracompany transferees employed with international firms;²⁷,32 H-1B professional specialty workers;²⁸,33 H-2A agricultural guest workers and H-2B nonagricultural guest workers;²⁹,34 J J cultural exchange visitors (including professors, students, foreign medical graduates, teachers, resort workers, camp counselors, and au pairs);, and F foreign students. In FY2019, for example, DOS consular officers issued 8.7 mil ion nonimmigrant visas, down from a peak of 10.9 mil ion in FY2015. There were approximately 6.5 mil ion tourism and business visas, which comprised about three-quarters of al nonimmigrant visas issued in FY2019. Other notable groups were temporary workers (963,000 or 11.0%), cultural exchange visitors (392,000 or 4.5%), and students (389,000 or 4.4%).35 Border Crossing Card Border crossing cards (BCC) al ow Mexican citizens who live in Mexico and and F foreign students.³⁰

Visa Waiver Program

Border Crossing Card

Mexican citizens who live in Mexico and who are admissible as B-1 business or B-2 tourist visitors can apply for a border crossing card (BCC) to gain short-term entry intoto briefly enter the United States. In FY2017, roughly 1.1 million Mexican nationals were issued border crossing cards.³³FY2020, DOS issued 662,536 border crossing cards to Mexican nationals.36 The BCC may be used for multiple entries and is usual y validand is valid usually for 10 years. Current rules limit BCC holders to visits of up to 30 days within a zone of 25 miles along the border in Texas and California, 55 miles along the New Mexico border, and 75 miles along the Arizona border.³⁴37 U.S. admissions from persons possessing border crossing cards in FY2016FY2019 totaled 104.6 mil ion.38 States. 31 Many temporary visa holders ultimately are able to adjust their status to LPR status after they have been admitted to the United States as nonimmigrants. In FY2019, for example, of the 1,031,765 foreign nationals who were granted lawful permanent resident status, 459,252 (44%) were new arrivals from abroad and 572,513 (56%) 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 2019 Yearbook of Im m igration Statistics, T able 6. 32 For more background, see archived CRS Report RL32030, Immigration Policy for Intracompany Transfers (L Visa): Issues and Legislation. 33 For more information, see archived CRS Report R43735, Temporary Professional, Managerial, and Skilled Foreign Workers: Policy and Trends. 34 For more information, see CRS Report R44849, H-2A and H-2B Temporary Worker Visas: Policy and Related Issues. 35 For statistics on nonimmigrant visas by category, see U.S. Department of State, Bureau of Consular Affairs, Report of the Visa Office 2020. 36 U.S. Department of State, Bureau of Consular Affairs, Report of the Visa Office 2020, T able XVI. 37 8 C.F.R. §212.6. 38 See DHS, 2019 Yearbook of Immigration Statistics, T able 25. BCC admissions are computed by subtracting “T otal I-94 admissions” from “ T otal all admissions” in T able 25. Admissions are events, not unique individuals. Congressional Research Service 8 Primer on U.S. Immigration Policy totaled 101.9 million.³⁵

Visa Issuance and Security

All In general, nonresident foreign nationals who wish to come to the United States, whether permanently or temporarily, must obtain a visa.39 A visa permits a foreign national to travel to a U.S. port of entry and request permission from CBP to enter the country. To obtain a visa, foreign nationals must establish their qualification for a specific visa under its admission criteria. Visa issuances to the United StatesIn addition, visa issuances can be denied under three main INA provisions:

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

Visa applications must be complete. Immigration applications and petitions almost al require fees.40 For example, a U.S. citizen wishing to sponsor his/her foreign-born spouse as an immediate relative must pay $535 when submitting a petition that establishes the familial relationship (USCIS Form I-130).41 If the spouse is living in the United States on a temporary nonimmigrant visa, the spouse must pay an additional $1,225 to apply to adjust to permanent resident status (USCIS Form I-485).42 If the spouse resides abroad, he/she must pay a $325 DOS processing fee43 and a $220 USCIS immigrant fee.44 As such, fees can represent a substantial financial outlay in some cases. The application must be complete.45 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 eligible to receive a visa. A consular officer may also disqualify a visa applicant if (1) he or /she knows or has reason to believe that 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.

All Al foreign nationals must undergo admissibility reviews. Consular officers must decide whether a foreign national is excludable under the grounds in INA Section 212(a), which include the following:

• health-related grounds;
• criminal grounds;
• security and terrorist concerns;
• public charge risk (e.g., indigence);³⁶
• seeking to work without proper labor certification;³⁷
• illegal U.S. entry and U.S. immigration law violations;
• ineligibility for U.S. citizenship; and
• following:  health-related grounds,  criminal grounds,46  security and terrorist concerns, 39 Exceptions to this rule include citizens or nationals of the (currently) 39 Visa Waiver Program (VWP) designated countries, Mexican and Canadian NAFT A Profession al Workers, and citizens of Canada and Bermuda. For more information, see CRS Report RL32221, Visa Waiver Program ; and U.S. Department of State, “ Travel Without A Visa,” https://travel.state.gov/content/travel/en/us-visas/tourism-visit/travel-without-a-visa.html. 40 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 archived CRS Report R44038, U.S. Citizenship and Im m igration Services (USCIS) Functions and Funding. 41 U.S. Citizenship and Immigration Services, “USCIS Immigrant Fee,” https://my.uscis.gov/uscis-immigrant-fee/. 42 Ibid. 43 Ibid. 44 Ibid. 45 Other costs may include legal fees, translation services fees, medical examination costs, fees related to the issuance of any required official documents, and travel expenses. 46 For more information, see CRS Report R45151, Immigration Consequences of Criminal Activity. Congressional Research Service 9 Primer on U.S. Immigration Policy  public charge risk (e.g., indigence),47  seeking to work without proper labor certification,48  previous il egal U.S. entry and U.S. immigration law violations,49  ineligibility for U.S. citizenship, and  having been previously removed from the United States.

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

For nonimmigrant applicants, aA visa denial under INA Section 214(b) indicates that the foreign national was unable to demonstrate to the consular officer that he or /she had sufficient ties to his or /her home country to return home.³⁸50 This is the most common reason that DOS denies nonimmigrant visas.

All In FY2019, 462,422 foreign nationals were issued immigrant visas, and 298,017 immigrant visa applications were initial y denied based on ineligibility findings (177,902 of which were ultimately overcome). In the same fiscal year, 8,742,068 foreign nationals were issued nonimmigrant visas, and 3,742,074 nonimmigrant applications were initial y denied based on ineligibility findings (830,177 of which were overcome).51 Al visa applicants are required to submit their photographs, fingerprints, and biographic and demographic information. All Visa applicants are checked against multiple databases and information sources for security purposes. Al prospective LPRs and certain prospective nonimmigrants must also submit to physical and mental examinations. Visa applicants are checked against multiple databases and information sources for security purposes. Consular officers' general y must be interviewed by a consular officer to determine whether they are qualified to receive a visa. Consular officers’ decisions on whether or not to grant foreign nationals a visa are not subject to judicial appeals.

Types of "Quasi-legal" Status

Two immigration mechanisms that allow persons to remain legally Visa applicants who were denied a visa for a particular ineligibility, and who meet certain conditions, may apply to DHS for a waiver of that ineligibility. Visa Waiver Program The Visa Waiver Program (VWP) al ows most citizens or nationals from participating countries to enter the United States as temporary visitors for business or pleasure without obtaining visas from U.S. consulates abroad. Those entering the country under the VWP undergo a biographic (e.g., name, address, date of birth) rather than a biometric (e.g., fingerprint) security screening and do 47 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. 48 For more information, see archived CRS Report RL33977, Immigration of Foreign Workers: Labor Market Tests and Protections. 49 Unauthorized aliens who were present illegally in the United States for between 6 and 12 months are barred from readmission to the United States for 3 years, and those present for more than 1 year are barred for 10 years (the “ 3 - and 10-year bars”). INA §212(a)(9)(B). 50 Some nonimmigrant visas, including H-1 professional workers, L intracompany transfers, K fiancé visas, and V accom panying family m em bers allow visa holders to simultaneously seek LPR status. T he same is true for beneficiaries of T and U nonimmigrant status (for victims of human trafficking and crime, respectively). Nonimmigrants seeking one of these visas or statuses do not need to prove t hey are not coming to reside permanently in the United States. 51 Note that applications refused does not necessarily equal the number of foreign nationals refused because an applicant can apply for a visa and be found ineligible more than once within the same fiscal year. Note also that a visa application may be denied in one fiscal year and overcome in a subsequent fiscal year. U.S. Department of State, Annual Report of the Visa Office 2019, T ables XV, XVI(B), and XX. Congressional Research Service 10 Primer on U.S. Immigration Policy not need to be interviewed by a U.S. government official before their trip.52 In FY2019, roughly 19.7 mil ion pleasure and 3.2 mil ion business visitors entered the United States using the VWP.53 Types of “Quasi-legal” Status Two immigration mechanisms that al ow persons to remain legal y in the United States without being legally legal y admitted into the country, Temporary Protected Status and parole, are described below. Other options that al ow persons to remain legal y in the United States without being legal y admittedbelow. Other options, including Deferred Enforced Departure, withholding of removal, and deferred action, are described in later sections of this report.

Temporary Protected Status

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 allowsal ows DHS, in consultation withw ith DOS, to grant Temporary Protected Status (TPS) to such foreign nationals, provided that doing so is consistent with U.S. national interests.³⁹54 Congress has also provided TPS legislatively.

While TPS beneficiaries may obtain employment authorization, TPS does not provide a path to LPR status. DHS can designate TPS for 6 to 18 months and may extend it if conditions do not change in the designated country. Based on the most recent designations for each country, there are an estimated 317,600320,000 TPS recipients from 10 countries: El Salvador, Haiti, Honduras, Nepal, Nicaragua, Somalia, South Sudan, South Sudan, Syria, and Yemen.⁴⁰

Parole

DHS may, at its discretion and on a case-by-case basis, "parole"55 In March 2021, the Biden Administration designated three more countries for TPS: Venezuela, Burma, and Haiti. An estimated 323,000 Venezuelans, 1,600 Burmese, and 100,000-150,000 Haitian nationals could be eligible to apply for TPS under these designations. The Trump Administration terminated TPS for six countries—El Salvador, Haiti, Honduras, Nepal, Nicaragua, and Sudan—but these terminations have not taken effect due to litigation. Certain Liberians and Venezuelans currently maintain relief under a similar administrative mechanism known as Deferred Enforced Departure (DED). Parole DHS may parole an alien into the United States for urgent humanitarian reasons or significant public benefit at its discretion and on a case-by-case basis. Parole is granted for a specified period and does not constitute formal admission to the United States. Parolees may obtain employment authorization but 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.56 52 For more information, see CRS Report RL32221, Visa Waiver Program . 53 See DHS, 2019 Yearbook of Immigration Statistics, T able 25. 54 INA §244, 8 U.S.C. §1254a. For more information, see CRS Report RS20844, Temporary Protected Status and Deferred Enforced Departure. 55 Figures for estimated T PS holders from individual countries come from Federal Register announcements. For more information on T PS countries, see https://www.uscis.gov/humanitarian/temporary-protected-status. 56 For more information, see CRS Report R46570, Immigration Parole. Congressional Research Service 11 Primer on U.S. Immigration Policy Naturalization Under U.S. immigration law, al public benefit. Parole does not constitute formal admission to the United States and is not classified as a formal immigration status (e.g., nonimmigrant, immigrant). It is granted for a specified period of time. Parolees may obtain employment authorization but must leave when the parole expires or, if eligible, be admitted in a lawful status.⁴¹

Naturalization

Under U.S. immigration law, all LPRs may become U.S. citizens through a process known as naturalization. With some exceptions, aliens must do the following to naturalize:

• residenaturalization requirements include the following:  residing continuously in the United States as LPRs for five years;
• demonstrate that they possess demonstrating possession of good moral character;
• demonstrate  demonstrating basic English skillsskil s and knowledge of U.S. history and civics; and
• take  taking an oath of allegienceal egience to the United States.57 Annual naturalizations averaged 717,195 between FY2010 and FY2019, with 843,593 foreign nationals naturalizing in FY2019.58 In 2019, census data indicate that an estimated 23.2 mil ion naturalized citizens resided in the United States, comprising 52% of the estimated 44.9 mil ion foreign-born U.S. residents.59 Immigration Enforcement Immigration enforcement involves the identification, investigation, apprehension, detention, prosecution, and deportation (removal) of foreign nationals who are inadmissible and/or violate U.S. laws and become removable. to the United States.⁴²

Immigration Enforcement

Immigration enforcement encompasses enforcement of the INA'INA’s civil provisions (e.g., violations of admission conditions) as well requirements) as wel as its criminal provisions (e.g., improper entry, marriage fraud, alien smuggling). It involvesCBP is responsible for border security where foreign nationals enter the United States (atat U.S. land, air, and sea ports of entry (POEs) and along U.S. borders (between ports of entry), as well asbetween POEs. ICE is responsible for enforcing immigration laws in the U.S. interior, including worksite enforcement.⁴⁴ Immigration enforcement also involves the identification, investigation, apprehension, prosecution, and deportation of foreign nationals who violate U.S. laws and become removable.

60 Border Security at Ports of Entry

Foreign nationals arrive in the United States at one of 329 ports of entry (POEs), including land checkpoints, airports, and seaportsany of the 329 land, air, and sea POEs. They are met by CBP officers whose primary immigration enforcement mission is to ensure that such travelers are eligible to enter the United States and to exclude inadmissible foreign nationals. Possession of a visa by a foreign national does not guarantee U.S. admission if a CBP officer finds the individual inadmissible under law.⁴⁵

About 390 million travelers (the law.61 In FY2019, about 410 mil ion travelers (U.S. citizens and noncitizens) entered the United States in FY2016, including roughly 251 million land travelers, 119 million air passengers and crew, and 20 million sea passengers and crew. During the same period, about 274, including roughly 249 mil ion land travelers, 136 mil ion air passengers and crew, and 26 mil ion 57 For more information, see CRS Report R43366, U.S. Naturalization Policy; and CRS In Focus IF10884, Expedited Citizenship through Military Service. 58 U.S. Department of Homeland Security, Yearbook of Immigration Statistics 2019, T able 20. 59 U.S. Census Bureau, 2019 American Community Survey data, 1-year estimates, accessed by CRS on January 5, 2021, at United States Census Bureau, “ Explore Census Data,” https://data.census.gov/cedsci/. Noncitizens include LPRs, lawful temporary nonresidents, and unauthorized aliens. DHS has estimated that 9.2 million of the estimated 13.6 million LPRs residing in the United States in 2019 were eligible to naturalize based on their length of time living in the country. See Bryan Baker, Estim ates of the Lawful Perm anent Resident Population in the United States and the Subpopulation Eligible to Naturalize: 2015-2019, DHS Office of Immigration Statistics, September 2019. 60 T his 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 https://www.gocoastguard.com/about -the-coast -guard/discover-our-roles-missions/migrant -interdiction. 61 INA 221(h), 8 U.S.C. §1201(h). Congressional Research Service 12 Primer on U.S. Immigration Policy sea passengers and crew. During the same period, about 288,000 aliens were denied admission and 13,000 aliens were denied admission and 21,000 aliens were arrested on criminal warrants.⁴⁶

To balance facilitating the flow of lawful travelers with the competing interest of ensuring border security and immigration enforcement, DHS relies on a risk management strategy that62 CBP has the dual responsibility for facilitating the flow of lawful travelers, immigrants, and trade while providing security at and between POEs against inadmissible persons and contraband.63 This includes screening at multiple points in the immigration process, beginning well wel before travelers arrive at U.S. POEs. DHS and other departments involved in the "inspection"inspection process use screening tools to distinguish known, low-risk travelers who may be eligible for expedited admissions processing from lesser-known, higher-risk travelers who are usuallyusual y subject to more extensive secondary inspections.⁴⁷

64 DHS is also responsible for implementing an electronic entry-exit system at POEs, a task Congress mandated in 1996. While CBP collects a portion of the requisite biographic and biometric data from noncitizens at various stages of their entry to and exit from the United States, the Government Accountability Office (GAO) reports that implementation of a fully automated biometric system has proven challenging.⁴⁸

chal enging. DHS has fully implemented the biometric entry system at al U.S. ports of entry. Reportedly, the biometric exit system currently captures information on about 60% of foreign nationals aged 14-79 departing the United States via commercial air carriers. Other technologies are gradual y being employed at air, sea, and land POEs.65 Border Security Between Ports of Entry Border Security Between Ports of Entry

Border security between POEs focuses onprotects against unauthorized land border entry into the United States, which has been a concern for Congress since the 1970s, when unauthorized migration first registered as a major national issue. ItBorder security has received greater attention since the terrorist attacks on September 11, 2001. CBP’s unauthorized migration control strategy between POEs strives for operational control, which the agency describes as “the ability to perceive and comprehend the operating environment (situational awareness), mobilize assets, infrastructure and barriers to prevent criminal activity (impedance and denial), and respond to and resolve any il icit cross-border incursions (response and resolution).”66 Impedance and denial, in particular, involve investments in physical infrastructure described below. They also encompass “enforcement with consequences,” which has received greater attention since the September 11, 2001, terrorist attacks.

CBP's unauthorized migration control strategy between POEs has involved "prevention through deterrence," or concentrating personnel, infrastructure, and surveillance technology along heavily trafficked border regions. More recently, CBP's strategy has involved "enforcement with consequences," which includes making migrants who commit crimes face criminal charges and incur penalties (including incarceration) prior to removal. For Mexican nationals, this can include repatriation to Mexican locations geographically remote from where migrants were apprehended. Criminal charges, penalties, and formal removal generally bar migrants from legally entering CBP’s border security strategies and investments include the construction and maintenance of tactical infrastructure, instal ation and monitoring of surveil ance technology, and the deployment of U.S. Border Patrol agents to prevent unlawful entries of people and contraband into the United States (e.g., unauthorized migrants, terrorists, firearms, narcotics). Tactical infrastructure includes 62 U.S. Department of Homeland Security, U.S. Customs and Border Protection, “CBP Enforcement Statistics Fiscal Year 2021,” https://www.cbp.gov/newsroom/stats/cbp-enforcement -statistics (for admission denied and arrest figures); U.S. Customs and Border Protection, “On a T ypical Day in Fiscal Year 2019, CBP…,” https://www.cbp.gov/ newsroom/stats/typical-day-fy2019 (for all other figures). Annual figures in text are derived by multiplying daily figures in the CBP source by 365. FY2020 statistics are available, but are not presented because the COVID -19 pandemic significantly limited international travel in that year. 63 For more information, see CRS Report R43356, Border Security: Immigration Inspections at Ports of Entry. 64 For more information, see CRS Report R46783, Trusted Traveler Programs. 65 For more information, see CRS In Focus IF11634, Biometric Entry-Exit System: Legislative History and Status. 66 U.S. Customs and Border Protection, 2020 U.S. Border Patrol Strategy, August 2019; and U.S. Customs and Border Protection Strategy 2021-2026, publication 1280-1220, December 2020. Congressional Research Service 13 Primer on U.S. Immigration Policy physical barriers between POEs which vary by age, purpose, form, and locationStates for varying lengths of time. Remote repatriation is intended to disrupt migrant smuggling networks and reduce the likelihood that removed migrants will reenter the country illegally.

The United States has substantially increased appropriations for personnel, fencing, infrastructure, and surveillance technology for border enforcement over the last three decades, particularly after 2001. Since receiving authorization from Congress in 1996, DHS has built 653 miles of several types of barriers along the U.S.-Mexico border, which spans nearly 2,000 miles.67 Tactical infrastructure also includes roads, gates, bridges, and lighting designed to support border enforcement and disrupt and impede il icit activity. Surveil ance technology assists CBP in the detection, identification, and apprehension of individuals il egal y entering the United States between POEs. Ground technology includes sensors, cameras, and radar tailored to fit specific terrain and population densities. Manned and unmanned aerial and marine surveil ance vessels patrol regions inaccessible by motor vehicle.68 In FY2019, 19,648 U.S. Border Patrol agents were stationed nationwide, with most (17,731) at the Southwest border.69 Apprehensions of unauthorized migrants, a widely cited border security metric, are positively related to unauthorized migrant flows.70the U.S.-Mexico border. CBP also employs land-based, aerial, and marine surveillance technologies.

The most widely cited metric of border security is unauthorized migrant apprehensions, which are usually positively related to the flow of unauthorized migrants.⁴⁹ Annual apprehensions were relatively low in the 1960s, climbed sharply after 1965, and reached peaks of roughly 1.7 millionmil ion in both 1986 and 2000. They have fallen since then to 310,531 apprehensions Since 2000, apprehensions general y declined, with some fluctuations, to a 46-year low of 310,531 in FY2017.71 Apprehension levels subsequently increased to 859,501 in FY2019 before declining to 405,036 in FY2020. They have since increased to 898,949 in the first eight months of FY2021.72 In March 2020, CBP curtailed its processing of those not considered essential travelers due to the global COVID-19 pandemic. Those affected included mostly asylum seekers arriving at the Southwest border. Under a public health order (referred to as Title 42) that was issued by the U.S. Department of Health and Human Services’ Centers for Disease Control and Prevention, CBP expel ed most migrants back to Mexico or in some cases their home countries.73 As of the cover date of this report, Title 42 was stil in effect for single adult migrants and some migrant families. In past years, debates centered on how much immigration enforcement affected migrant flows compared with other factors like the U.S. unemployment rate.74 More recently, some commentators have cited both anticipation and enactment of more or less restrictive policies by 67 For more information, see CRS Report R45888, DHS Border Barrier Funding; and CRS Insight IN11193, Funding U.S.-Mexico Border Barrier Construction: Current Issues. 68 See archived CRS Insight IN11040, Border Security Between Ports of Entry: Homeland Security Issues in the 116th Congress. 69 U.S. Customs and Border Protection, U.S. Border Patrol Fiscal Year Staffing Statistics (FY 1992 - FY 2019), accessed June 7, 2021, https://www.cbp.gov/sites/default/files/assets/documents/2020-Jan/U.S.%20Border%20Patrol%20Fiscal%20Year%20Staffing%20Statistics%20%28FY%201992%20 -%20FY%202019%29_0.pdf. 70 See for example, T homas J. Espenshade, “ Using INS Border Apprehension Data to Measure the Flow of Undocumented Migrants Crossing the U.S.-Mexico Frontier,” International Migration Review, vol. 29 (Summer 1995), pp. 545-565. For more on border security metrics, see archived CRS Report R44386, Border Security Metrics Between Ports of Entry. Apprehension figures include those at the northern, southern and coastal borders. See also U.S. Department of Homeland Security, Border Security Metrics Report, August 5, 2020. 71 U.S. Customs and Border Protection, “Stats and Summaries,” Nationwide Illegal Alien Apprehensions, Fiscal Years 1925-2019, at https://www.cbp.gov/newsroom/media-resources/stats. 72 U.S. Customs and Border Protection, “CBP Enforcement Statistics Fiscal Year 2021,” at https://www.cbp.gov/newsroom/stats/cbp-enforcement-statistics. In March, 2020, apprehension statistics were expanded to include expulsions under T itle 42 (Public Health) of the U.S. code. T he CBP currently reports statistic s for encounters which include both T itle 8 apprehensions and T itle 42 expulsions. 73 CRS Report R46755, The Law of Asylum Procedure at the Border: Statutes and Agency Implementation. 74 For more information, see archived CRS Report R42138, Border Security: Immigration Enforcement Between Ports of Entry. Congressional Research Service 14 Primer on U.S. Immigration Policy the Trump and Biden Administrations, respectively, as an additional cause of fluctuations in apprehension levels.75 Detention The INA authorizes—and in some cases requires—DHS to detain foreign nationals who are subject to removal from the United States. Detention rules are multifaceted and depend on several factors, such as whether the individual is seeking admission or has been lawfully admitted into the country, has engaged in certain proscribed conduct, and has been issued a final order of removal. Four INA provisions provide a framework for immigration detention:  INA Section 236(a) general y authorizes the detention of aliens pending a decision on whether the alien is to be removed from the United States and permits those who are not subject to mandatory detention to be released on bond or their own recognizance;  INA Section 236(c) general y requires the detention of aliens who are removable because of specified criminal activity or terrorism-related grounds;  INA Section 235(b) general y requires the detention of applicants for admission who appear subject to removal, including aliens arriving at a POE and certain other aliens who have not been admitted or paroled into the United States; and  INA Section 241(a) general y requires an alien subject to a final order of removal to be held during the 90-day period when the alien’s removal is effectuated. DHS may detain an alien beyond 90 days if the agency cannot effectuate removal and the alien fal s within certain categories.76 DHS detained 510,854 aliens during FY2019.77 The amount of detention space is controlled largely through congressional appropriations. ICE must obtain travel documents to repatriate removable in FY2017.⁵⁰ The extent to which reduced inflows resulted from more effective enforcement rather than other factors, like the U.S. economic downturn in the late 2000s, remains subject to debate.⁵¹

Detention

The U.S. Supreme Court has ruled that the detention of unauthorized foreign nationals generally may not last beyond six months. In addition, ICE must obtain travel documents to repatriate foreign nationals. Because some countries refuse to provide suchtravel documents or do so in a protracted mannerdelay doing so, ICE has regularly released sizeable numbers of detainees following their full detention term, including criminal aliens—an outcome that has been criticized repeatedly by some Members of Congress.⁵⁴

Removal

Removing foreign nationals who violate U.S. immigration 78 The U.S. Supreme Court has ruled that foreign nationals who are subject to a final removal order and are facing indefinite detention pending DHS’s efforts to secure their removal general y may not be detained for more than six months.79 75 For more information, see CRS Report R46012, Immigration: Recent Apprehension Trends at the U.S. Southwest Border and CRS Report R45489, Recent Migration to the United States from Central Am erica: Frequently Asked Questions. 76 For more information on standards and criteria for making detention decisions, see CRS In Focus IF11343, The Law of Im m igration Detention: A Brief Introduction ; and CRS Report R45915, Im m igration Detention: A Legal Overview. 77 U.S. Department of Homeland Security, Office of Immigration Statistics, Annual Flow Report, Immigration Enforcem ent Actions: 2019, T able 5, September 2020. 78 U.S. Congress, House Committee on the Judiciary, Oversight of United States Immigration and Customs Enforcem ent, opening statement of the Honorable Bob Goodlatte, Chairman , 114th Cong., 2nd sess., September 22, 2016. For more information, see CRS In Focus IF11343, The Law of Im m igration Detention: A Brief Introduction ; and archived CRS Report RL32369, Im migration-Related Detention. 79 Zadvydas v. Davis, 533 U.S. 678, 693 (2001). Congressional Research Service 15 Primer on U.S. Immigration Policy Removal Removing foreign nationals who violate U.S. immigration and other laws is central to laws is central to immigration enforcement, and the INA provides broad authority to DHS and DOJ to remove certain foreign nationals from the country. This includesThese persons include unauthorized aliens as well wel as lawfully present foreign nationals who commit certain acts that make them removable. Any foreign national found to be inadmissible (either before or after U.S. entry) or deportable under grounds specified in the INA may be ordered removed.

To remove a To remove a foreign national who has already been lawfully admitted alien, the U.S. government must prove that the noncitizen individual has violated one of the following six grounds of deportation specified in INA Section 237(a):

•  being inadmissible at the time of entry⁵⁵entry80 or violating one'’s immigration status;
•  committing certain criminal offenses, including crimes of "“moral turpitude," ” aggravated felonies, alien smuggling, and high-speed flight from an immigration checkpoint;⁵⁶
• 81  failing to register with DHS (if required) or committing document fraud;
•  being a security risk (including violating any law relating to espionage, engaging in criminal activity that endangers public safety, partaking in terrorist activities, or assisting in Nazi persecution or genocide);
•  becoming a public charge within five years of entry; or
•  voting unlawfully.

The INA describes procedures for making and reviewing a removalremovability determination, and specifies conditions under which certain grounds of removal may be waived. DHS officials may exercise some discretion in pursuing removal orders, and certain removable aliens may be eligible for permanent or temporary relief from removal. Other grounds for removal (e.g., criminal, terrorist)some criminal offenses, terrorist activities) may render foreign nationals ineligible for most forms of relief and may make them subject to a more streamlined (expedited) removal processesremoval process, both at the U.S. border and within the U.S. interior.

Under the standard removal process, an immigration judge from EOIR determines in a civil judicial proceeding whether an aliena foreign national is removable. The immigration judge may grant certain forms of relief (e.g., asylum, cancellationcancel ation of removal), and removal decisions are subject to administrative and judicial review.

Under streamlined removal procedures, including expedited removal and reinstatement of removal (i.e., when DHS reinstates a removal order for a previously removed alien), individual), opportunities for relief and review are generallygeneral y limited. Under expedited removal (INA §235(b)), an alien who who is inadmissible because he/she lacks proper documentation or has committed fraud or willful misrepresentation to gain admission into the United States is inadmissible. That individual or wil ful misrepresentation to gain U.S. admission may be removed without any further hearings or review, unless he or /she indicates an intention to apply for asylum.

Two other removal options that are often referred to as "returns" 80 Grounds of inadmissibility are outlined in INA Section 212, 8 U.S.C. Section 182. If individuals are removed because they were inadmissible at the time of entry, they are removed under INA Section 212, not INA Section 237. 81 Crimes of moral turpitude are determined by case law. For more information, see CRS Report R45151, Immigration Consequences of Crim inal Activity. Congressional Research Service 16 Primer on U.S. Immigration Policy Two options that are often referred to as returns—voluntary departure and withdrawal of petition for admission—require aliensforeign nationals to leave the United States promptly but exempt them from certain penalties associated with other types of removal.

Following an order of removal, an alien is generally ineligible removal. Fol owing an order of removal, a foreign national is general y ineligible to return to the United States for a minimum of five years and possibly longer depending on the reason for and type of removal. Absent other factors, unlawful presence in the United States is a civil violation, not a criminal offense, and removal and its associated administrative processes are civil proceedings. As such, alienspersons in removal proceedings generallygeneral y have no right to free government-provided counsel, although they may obtain counsel at their own expense.⁵⁷

82 Programs Targeting Criminal Aliens

Although all Although al unauthorized aliens are potentiallypotential y subject to removal, the removal of criminal aliens (noncitizens who have been convicted of a crime in the United States) has been a statutory priority since 1986.83 Programs targeting criminal aliens for removal have grown substantially substantial y since DHS was established in 2002.

ICE currently operates several programs thatto identify and remove criminal and other removable aliens, including the Criminal Alien Program (CAP), an umbrellaumbrel a program for coordinating the agency' agency’s resources.⁵⁸84 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 jail.

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 (NFOP). In addition to programs using DHS personnel, ICE'’s Section 287(g) program allowsal ows DHS to delegate certain immigration enforcement functions to specially special y trained state and local law enforcement officers, under federal supervision.⁵⁹

85 Options for Aliens in Removal Proceedings

Provisions in the INA INA provisions permit certain removable aliens to remain in the United States, either permanently or temporarily.⁶⁰86 Options that provide permanent relief by conferring or leading to lawful permanent resident status include cancellationcancel ation of removal (discussed above) and "defensive" defensive asylum applied for during removal proceedings.⁶¹87 Options that provide temporary relief include 82 For more information, see CRS In Focus IF11357, Expedited Removal of Aliens: An Introduction; CRS Legal Sidebar LSB10150, Im m igration Laws Regulating the Adm ission and Exclusion of Aliens at the Border; and CRS Report R43892, Alien Rem ovals and Returns: Overview and Trends. 83 T he Immigration Reform and Control Act (P.L. 99-603) made deporting aliens who had been convicted of certain crimes a formal enforcement priority. T he law required the Attorney General “in the case of an alien who is convicted of an offense which makes the alien subject to deportation … [to] begin any deportation proceeding as expeditiously as possible after the date of the conviction.” 84 For more information, see CRS Insight IN11335, COVID-19’s Effect on Interior Immigration Enforcement and Detention; and CRS Legal Sidebar LSB10362, Im m igration Arrests in the Interior of the United States: A Prim er. 85 For background information, see archived CRS Report R44627, Interior Immigration Enforcement: Criminal Alien Program s. 86 For more information on permanent and temporary forms of relief from removal, see CRS Report R43892, Alien Rem ovals and Returns: Overview and Trends. 87 Applying for asylum while in removal proceedings is referred to as a defensive claim because it acts as a defense to one’s removal. In contrast, affirmative asylum claims typically occur upon arrival to the United States. For more information, see CRS Report R45539, Im m igration: U.S. Asylum Policy. Congressional Research Service 17 Primer on U.S. Immigration Policy withholding of removal, Convention Against Torture (CAT) protection, Deferred Enforced Departure, and deferred action. Withholding of removal may be given to foreign nationals who can demonstrate a clear probability (above 50%) 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 deportation to a country where they fear persecution. Unlike asylum, an immigration judge has no discretion and must grant withholding of removal to alien applicants who meet the requirements.88 CAT is a rarely granted protection from removal for individuals who fear torture in their home country. To qualify, applicants must demonstrate a clear probability (above 50%) that they wil be tortured directly by or with the acquiescence of the government of their country of origin.89 Deferred Enforced Departure (DED), which is granted based upon the executive branch’s independent constitutional authority rather than any specific statutory authority, al ows aliens relief from removal from the United States for a designated period of time. Aliens receive DED while in removal proceedings. The Administration may use its discretion when applying DED by balancing foreign policy, humanitarian, and immigration concerns.90 Deferred action is defined by DHS as “a discretionary determination to defer removal action of an individual as an act of prosecutorial discretion.” Deferred action is not an immigration status and lacks Options that provide temporary relief include withholding of removal,⁶² the Convention Against Torture,⁶³ Deferred Enforced Departure,⁶⁴ and deferred action (described below).

Worksite Enforcement

The INA prohibits the employment of individuals who lack work authorization.⁶⁵ Its provisions, sometimes referred to as employer sanctions, make it unlawful for an employer to knowingly hire, recruit or refer for a fee, or continue to employ an alien who is not authorized to be so employed. ICE's worksite enforcement program primarily targets cases involving critical infrastructure or employers who commit "egregious" violations of criminal statutes and engage in worker exploitation. Employers who violate prohibitions on unauthorized employment may be subject to civil monetary penalties and/or criminal penalties.⁶⁶

Combatting Immigration Fraud

Unauthorized Aliens

Because the exact number of unauthorized aliens residing in the United States remains unknown, demographers have developed methods to estimate their population size and characteristics.⁷² According to the most recent and widely cited estimates available, the size of the unauthorized alien population increased from 8.6 million in 2000 to a peak of 12.2 million in 2007. It has fluctuated between 11.0 and 11.5 million since that time.⁷³ Scholars attribute the general decline and changing country-of-origin composition in illegal migration flows in recent years to increased border security, relatively large numbers of alien removals, high U.S. unemployment, crime in Central America, and other factors.⁷⁴

Immigration Law Regarding Unauthorized Aliens

Deferred Action

For unauthorized aliens who cannot obtain LPR status, existing mechanisms enable some to remain in the United States. One such mechanism, deferred action, is defined by DHS as "a discretionary determination to defer removal action of an individual as an act of prosecutorial discretion." Deferred action is not an immigration status and does not have a statutory authority; it is a form of administrative discretion a statutory authority; it is a form of administrative discretion. Persons for whom deferred action is in effect are not considered to be unlawfully present. Examples of deferred action may include DHS terminating removal proceedings, declining to initiate removal proceedings, or declining to execute a final order of removal. Approval of deferred action means that no action will wil be taken against a removable  alien for a specified time or, in some cases, indefinitely.

91 Under the Deferred Action for Childhood Arrivals (DACA) initiative begun by DHS in June 2012, certain individuals without a lawful immigration status who were brought to the United States as children and who meet other criteria may be granted deferred action for two years, subject to renewal. DACA recipients can apply for employment authorization but are not afforded a pathway to a legal immigration status. DACA was initiated not by congressional legislation but by the Obama Administration.DACA was initiated in 2012 by the Obama Administration through an executive branch memorandum.92 The Trump Administration announced the planned rescission of the DACA initiative initiative on September 5, 2017, but due to federal court orders enjoining the rescission, DACA remains in effect.93 88 For more information, see CRS Report R45539, Immigration: U.S. Asylum Policy. 89 For more background, see archived CRS Report RL32276, The U.N. Convention Against Torture: Overview of U.S. Im plem entation Policy Concerning the Rem oval of Aliens (available to congressional clients upon request to CRS). 90 For more information, see CRS Report RS20844, Temporary Protected Status and Deferred Enforced Departure. 91 For more information, see U.S. Citizenship and Immigration Services, “Consideration of Deferre d Action for Childhood Arrivals (DACA), Frequently Asked Questions,” February 4, 2021; and National Immigration Forum, “Deferred Action Basics,” April 15, 2016. 92 For moreremains in effect pending the outcome of further litigation.⁷⁷