Source: https://www.everycrsreport.com/reports/R42866.html
Timestamp: 2019-04-23 21:54:09+00:00

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Four major principles currently underlie U.S. policy on legal permanent immigration: the reunification of families, the admission of immigrants with needed skills, the protection of refugees and asylees, and the diversity of immigrants by country of origin. These principles are embodied in the Immigration and Nationality Act (INA) and 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. Humanitarian assistance occurs primarily through the U.S. refugee and asylee programs. Origin-country diversity is addressed through the Diversity Immigrant Visa.
In addition to the primary components of permanent immigration discussed above, there are several other pathways to lawful permanent resident (LPR) status, though they account for relatively few immigrants. The most prominent among these are cancellation of removal for aliens in removal proceedings, U nonimmigrant visas for alien crime victims who assist law enforcement agencies, and T status for alien victims of human trafficking.
The pool of people eligible to immigrate to the United States as LPRs each year typically exceeds numerical limits established by the INA for most immigrant pathways. In an effort to process the demand for LPR visas fairly and in accordance with the national interest, the INA imposes a complex set of numerical limits and preference categories within major immigrant pathways that admit LPRs to the United States on the basis of family relationships, needed skills, and geographic diversity.
The INA limits worldwide permanent immigration to 675,000 persons annually: 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 immigrants; and 55,000 diversity visa immigrants. This worldwide limit, however, is referred to as a “permeable cap,” because certain categories of LPRs are not subject to numerical limitations. These include immediate relatives of U.S. citizens within the INA’s family-sponsored immigration provisions, as well as refugees whose number is determined by the President in consultation with Congress. In addition, the number of persons granted asylum is not numerically constrained. Consequently, the number of persons receiving LPR status each year regularly exceeds the INA’s statutory worldwide level for permanent immigration.
The INA further specifies that countries are held to a numerical limit of 7% of the annual worldwide level of family-sponsored and employment-based immigrants, known as the per-country limit or country cap. The cap is intended to prevent one or just a few countries from dominating immigrant flows.
In FY2016, almost 1.2 million aliens became LPRs. Of this total, 68% became LPRs through family-sponsored provisions of the INA. Other major LPR categories included refugees and asylees (13%), employment-based immigrants (12%), and diversity visa immigrants (4%). While 618,078 LPRs (52%) in FY2016 were granted LPR status upon their admission to the United States from abroad, 565,427 (48%) adjusted to LPR status from a temporary (i.e., nonimmigrant) status from within the United States. In FY2016, Mexico accounted for the largest proportion (15%) of LPRs who were admitted from abroad or adjusted status from within the United States. Other top immigrant source countries included China (7%), Cuba (6%), India (5%), and the Dominican Republic (5%).
At the start of FY2018, approximately 4.1 million approved LPR visa petitions—almost all family-sponsored petitions—were pending with the Department of State’s National Visa Center because of the numerical limits in the INA. Approximate wait times for numerically limited family and employment preference visas range widely depending on the specific preference category and country of origin. Prospective family-sponsored immigrants from China, Mexico, India and the Philippines have the most substantial wait times before a visa is scheduled to become available to them.
Those who favor reduced immigration have supported proposals to limit family-sponsored LPRs to the immediate relatives of U.S. citizens, to confine employment-based LPRs to highly skilled workers, to admit employment-based immigrants using some type of merit-based system, and to eliminate the diversity visa.
The INA limits worldwide permanent immigration to 675,000 persons annually: 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 immigrants; and 55,000 diversity visa immigrants. This worldwide limit, however, is referred to as a "permeable cap," because certain categories of LPRs are not subject to numerical limitations. These include immediate relatives of U.S. citizens within the INA's family-sponsored immigration provisions, as well as refugees whose number is determined by the President in consultation with Congress. In addition, the number of persons granted asylum is not numerically constrained. Consequently, the number of persons receiving LPR status each year regularly exceeds the INA's statutory worldwide level for permanent immigration.
At the start of FY2018, approximately 4.1 million approved LPR visa petitions—almost all family-sponsored petitions—were pending with the Department of State's National Visa Center because of the numerical limits in the INA. Approximate wait times for numerically limited family and employment preference visas range widely depending on the specific preference category and country of origin. Prospective family-sponsored immigrants from China, Mexico, India and the Philippines have the most substantial wait times before a visa is scheduled to become available to them.
Some have advocated for a significant reallocation of the visa categories or a substantial increase in legal immigration to satisfy the desire of U.S. families to reunite with their relatives abroad and to meet the labor force needs of U.S. employers. Proponents of family-sponsored migration often maintain that proposals to increase immigration should include additional family-sponsored visas to more quickly reunify families by reducing wait times—currently up to years and decades—for those already "in the queue."
Despite extensive critiques of the permanent legal immigration system, no consensus exists on the specific direction reforms to the system should take. Some maintain that revising provisions governing legal permanent immigration should be a key component of any major immigration reform proposal, while others support the existing provisions and their underlying rationales. This report on legal permanent immigration may help inform the debate and discussions of policy options that may emerge as Congress considers current immigration proposals.
Legal aliens3 are of three main types: immigrants, nonimmigrants and refugees. As defined in the INA, immigrants are synonymous with lawful permanent residents (LPRs) and refer to foreign nationals who come to live lawfully and permanently in the United States. Nonimmigrants—such as tourists, foreign students, diplomats, temporary agricultural workers, exchange visitors, or intracompany business personnel—are admitted for a specific purpose and a temporary period of time.4 Nonimmigrants must leave the United States before their visas expire, although certain classes of nonimmigrants may adjust to LPR status if they otherwise qualify.5 Refugees and asylees are people fleeing their countries because of persecution or a well-founded fear of persecution. After one year in refugee status in the United States, refugees must apply to adjust to LPR status. In contrast, asylees may, but are not required to, apply for LPR status after one year.
Prospective immigrants must maneuver a multi-step process through federal departments and agencies to obtain LPR status. First, petitions for LPR status are filed with U.S. Citizenship and Immigration Services (USCIS) in the Department of Homeland Security (DHS) by the prospective immigrant or by the sponsoring relative or employer in the United States (in the case of family-sponsored or employment-based immigration, respectively). If the prospective LPR is residing abroad or has not established a lawful residence in the United States, the petition is forwarded to the Department of State's (DOS) Bureau of Consular Affairs in the alien's home country after USCIS has approved it. If the prospective immigrant is already legally residing in the United States, USCIS handles most of the process, which the INA refers to as "adjustment of status" because the alien is moving from a temporary status to LPR status. Roughly half of all persons granted LPR status in FY2016—the most recent year for which such data are available—did so by adjusting status.
Immigrant admissions and adjustments to LPR status are subject to complex numerical limits and preference categories that give priority for admission on the basis of family relationships, needed skills, and geographic diversity. In addition, immigrants who enter through the family-sponsored and employment based preference categories are subject to a 7% per-country cap (see "Per-country Ceilings" below).9 Numerical limits on immigration combined with the per-country cap for some categories has resulted in a sizable "visa queue" of foreign nationals with approved immigration petitions who must wait until a numerically limited visa becomes available before they can immigrate permanently to the United States (see "The Visa Queue" below).
As a result, the actual number of immigrants who receive LPR status varies from year to year according to the prior year's number of immediate relative immigrants, parolees, and unused employment-based preference immigrant visas that roll over.
Congress has enacted two important exceptions to the per-country ceilings. The first exception allows 75% of the visas allocated to the 2nd family preference category (2A) of spouses and children of LPRs to be exempt from the per-country ceiling (see Table 1 for family preference categories).19 The second exception allows the 7% per-country ceiling for employment-based immigrants to be surpassed for individual countries that are oversubscribed if visas are available within the 140,000 worldwide limit for employment-based preferences.20 The impact of these revisions to the per-country ceilings is discussed later in this report.
Source: CRS summary of INA §§203(a), 203(b), and 204, (8 U.S.C. §§1153(a) 1153(b), and 1154).
Notes: children refer to unmarried minors under age 21; sons and daughters refer to children ages 21 and older.
The diversity immigrant visa fosters legal immigration from countries that send relatively few immigrants to the United States.25 Each year, 50,000 visas are made available to selected natives of countries from which immigrant admissions totaled less than 50,000 over the preceding five years.26 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. 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. Applicants are selected by lottery whose winners must also meet the standard eligibility criteria required for most immigrants.
Several other pathways apart from family-sponsored and employment-based immigrants allow persons to acquire LPR status. They range from aliens in removal (i.e., deportation) proceedings who are granted LPR status by an immigration judge, victims of crime and human trafficking, and refugees and asylees who adjust to LPR status.27 Table 2 summarizes these major pathways and any related numerical limitations.
Source: CRS summary of INA §203(a) (8 U.S.C. §1153(a)), INA §203(b) (8 U.S.C. §1153(b)), INA §204 (8 U.S.C. §1154), INA §207 (8 U.S.C. §1157), INA §208 (8 U.S.C. §1158), and INA §240A (8 U.S.C. §1229b).
a. For more information on cancellation of removal, see CRS Report R43892, Alien Removals and Returns: Overview and Trends.
b. For more information on U visas, see CRS Report R42477, Immigration Provisions of the Violence Against Women Act (VAWA).
c. For more information on T nonimmigrant status, see CRS Report RL34317, Trafficking in Persons: U.S. Policy and Issues for Congress.
d. For more information, see CRS Report RL31269, Refugee Admissions and Resettlement Policy, by Andorra Bruno.
Immigration to the United States (Figure 1) is determined by many factors apart from U.S. immigration laws. Push factors from immigrant-sending countries include civil wars, political unrest, economic deprivation, limited job opportunities, and catastrophic natural disasters. Pull factors from the United States include relatively strong employment prospects, opportunities to reunite with family members, and quality of life considerations. A corollary factor is the extent to which aliens can migrate to other countries offering circumstances and opportunities comparable to, or better than, the United States.
U.S. immigration, which experienced several peaks between the late 19th and early 20th Centuries declined considerably as the result of the Great Depression and World War II. The annual number of persons acquiring LPR status who were admitted from abroad or adjusting status from within the United States rose gradually after World War II and continued steadily for three decades, partly as the result of war refugee admissions as well as a growing U.S. economy.
After 1980, immigration growth occurred for a number of reasons. First, the Immigration Reform and Control Act of 1986 (IRCA, P.L. 99-603) legalized 2.7 million aliens who were residing in the United States without authorization. These newly legalized individuals were then eligible to sponsor other family members, either as LPRs or, for those who subsequently naturalized, as U.S. citizens.
Second, the Immigration Act of 1990 (P.L. 101-649) increased the ceiling on employment-based preference immigration and included a provision allowing unused employment-based preference visas to be made available the following year for family-sponsored preference immigration and vice versa for unused family-sponsored preference visas. Third, following the enactment of the Refugee Act of 1980 (P.L. 96-212), the number of refugees admitted increased from 718,000 for the 15-year period between 1966 and 1980 to 1.6 million between 1981 and 1995.
Source: U.S. Department of Homeland Security, Office of Immigration Statistics (OIS), Yearbook of Immigration Statistics, multiple fiscal years.
Note: Aliens legalizing through the Immigration Reform and Control Act (IRCA) of 1986 are depicted by year of adjustment.
In any given period of U.S. history, a handful of countries have dominated the flow of immigrants, but the dominant countries have changed over time. Figure 2 presents the countries from where the most individuals emigrated and together comprised at least half of all immigrants for selected decades. The figure illustrates two points. First, while immigration at the start of the 20st century was dominated by three or four countries, immigration at the start of the 21st century originated from a much broader set of countries. Second, these data suggest that the per-country ceilings established by the Immigration and Nationality Act Amendments of 1965 had a considerable impact on this shift in country-of-origin composition.
Source: CRS analysis of Table 2, Statistical Yearbook of Immigration, U.S. Department of Homeland Security, Office of Immigration Statistics, FY2010.
Notes: Decades presented were chosen at 20-year intervals, except 1940-1949 which was not presented because of the major disruptions to immigration flows during World War II.
Figure 2 also illustrates the change in geographic origin of U.S. immigration. Most immigrants during the early 20th century originated from European countries, such as Germany, Italy, Austria-Hungary, and the United Kingdom. Mexico has been a top sending country for most of the 20th century and into the 21st century. Most immigrants in more recent decades originate from Western Hemisphere countries such as the Dominican Republic, Cuba, Haiti, Jamaica, and Colombia, and Asian countries including China, India, the Philippines, Vietnam, and South Korea.
In FY2016, approximately 1.2 million aliens became LPRs, either by being admitted as such upon arrival to the United States from overseas, or by adjusting to LPR status from a nonimmigrant status while in the United States (Figure 3). Of this total, just over two-thirds acquired LPR status as family-sponsored immigrants. Employment-based immigrants (12%) and refugees and asylees (13%) make up another quarter, and diversity immigrants (4%), and all other classes of immigrants (3%) make up the remainder.
Source: U.S. Department of Homeland Security, Office of Immigration Statistics, FY2016 Yearbook of Immigration Statistics, Table 6.
Source: U.S. Department of State, Annual Report of Immigrant Visa Applicants in the Family-Sponsored and Employment-Based Preferences Registered at the National Visa Center as of November 1, 2017.
Family-sponsored preference immigrants dominated the queue of 4.06 million approved LPR visa petitions pending with the National Visa Center at the end of FY2017 (Figure 4). Over half (58%) of all approved petitions pending were 4th preference siblings of U.S. citizens, and one-quarter (25%) were 1st preference unmarried adult children and 3rd preference married adult children of U.S. citizens. Second preference family members of LPRs totaled 14% of the queue.
Table 3 presents information from a recent Visa Bulletin published monthly by the Department of State for all five family-sponsored preference categories. It indicates that, as of February 9, 2018 (the date when the March Visa Bulletin was published), relatives of U.S. citizens and LPRs who fell into all five of these categories and who had approved immigration petitions were waiting for a visa to become available. As such, it reflects the consequences of both numerical limits for family-sponsored and employment-based preference immigrants as well as the 7% per-country cap on those LPR categories.
Source: U.S. Department of State, Bureau of Consular Affairs, Visa Bulletin for March 2018, February 9, 2018.
Notes: The "F" codes are used by DOS in its Visa Bulletin to refer to the various family-sponsored preference categories. The second family-sponsored preference category is divided into two groups: 2nd Preference A, consisting of spouses and minor children of LPRs; and 2nd Preference B, consisting of adult unmarried children of LPRs. USCs refer to U.S. citizens, and LPRs refer to lawful permanent residents.
According to the March 2018 Visa Bulletin (Table 3), DOS was processing visa petitions, as of February 9, 2018, for unmarried adult sons and daughters of U.S. citizens (1st preference) from India whose immigration petitions were submitted to USCIS on March 22, 2011. Depending on the country of origin, persons in this category who had submitted petitions even earlier were also being processed for visas. Likewise, as of February 9, 2018, DOS was processing visa petitions for married adult sons and daughters of U.S. citizens from China (3rd preference) whose immigration petitions were submitted to USCIS more than 12 years ago (December 15, 2005). Depending on the country of origin, persons in this category who had submitted petitions even earlier were also being processed for visas.
Brothers and sisters of U.S. citizens (4th preference) could expect to wait over 13 years, with considerably longer waits for siblings from Mexico and the Philippines. DOS consular officers, as of February 9, 2018, were adjudicating visa petitions of brothers and sisters of U.S. citizens from the Philippines who had filed immigration petitions over 23 years ago.39 In contrast, spouses and minor children of LPRs (category F2A in Table 3) for all countries had the most recent priority date of March 22, 2016, indicating that DOS consular officers were adjudicating visa petitions submitted approximately two years ago.
Table 4 presents information from the March 2018 Visa Bulletin for the five employment preference categories. It indicates that, as of February 9, 2018, categories for all worker visas were current. However, workers applying to emigrate from countries that send large numbers of employment-based immigrants to the United States faced waiting times for specific categories. For example, those seeking advanced degree visas from China and India had December 8, 2013, and December 15, 2008, priority dates, respectively. Visas granted for professional and skilled workers were current, except for workers from China, India and the Philippines, who faced waiting times.
Source: U.S. Department of State, Bureau of Consular Affairs, Visa Bulletin for March 2018.
Those favoring expanded immigration typically advocate for specific changes. Some favor a significant reallocation of the visa categories or a substantial increase in legal immigration to satisfy the desire of U.S. families to reunite with their relatives still abroad and to meet the labor force needs of employers hiring foreign workers. Others favor a reallocation toward employment-based immigration to help U.S. employers compete for the "best and the brightest," including foreign professional workers in science, technology, engineering, or mathematics (STEM) fields. Proponents of family-sponsored migration maintain that any proposal to increase immigration levels generally should also include the option of additional family-sponsored visas to reduce wait times—currently up to years or decades—for those already "in the queue."
Those who favor reduced immigration contend that family-sponsored immigration permits relatively large numbers of foreign nationals to permanently settle in the United States without regard to their skill, education levels, or potential contribution to the U.S. economy. Some argue that family-sponsored immigration should be limited to immediate relatives of U.S. citizens and LPRs. Others favor revising employment-based immigration so that immigrants are selected on the basis of "merit-based" criteria (e.g., educational attainment, employment in a high demand field, English language skills, age) rather than largely being sponsored by employers under the current system. Many in Congress also support eliminating the Diversity Immigrant Visa which they contend poses security risks and requires relatively little in terms of skill and education requirements.
P.L. 89-236, also known as the Immigration and Naturalization Act of 1965 and the Hart-Celler Act.
Congress has significantly amended the INA numerous times since 1952. Other major laws amending the INA include the Refugee Act of 1980, the Immigration Reform and Control Act of 1986, and the Illegal Immigration Reform and Immigrant Responsibility Act of 1996. 8 U.S.C. §1101 et seq.
INA 101(a)(3) defines the term "alien" as a noncitizen. In this report, alien is synonymous with the terms "noncitizen" and "foreign national."
Nonimmigrants are often referred to by the letter that denotes their specific provision in the statute, such as H-2A agricultural workers, F-1 foreign students, or J-1 cultural exchange visitors. For more information, see CRS Report R45040, Nonimmigrant (Temporary) Admissions to the United States: Policy and Trends, by Jill H. Wilson.
Ibid. In addition, INA §245 details the circumstances under which an alien can change from a nonimmigrant or other temporary status to LPR status without leaving the United States to apply for an LPR visa.
For background on the naturalization process, see CRS Report R43366, U.S. Naturalization Policy, by William A. Kandel.
For information on grounds for deportability, see CRS Report R43892, Alien Removals and Returns: Overview and Trends, by Audrey Singer.
These include criminal, national security, health, and indigence grounds as well as past violations of immigration law. INA §212(a); 8 U.S.C. §1182. For background information, see CRS Report R41104, Immigration Visa Issuances and Grounds for Exclusion: Policy and Trends, by Ruth Ellen Wasem.
§202(a)(2) of the INA; 8 U.S.C. §1152(a)(2).
INA §201(b)(2)(A)(i) defines "immediate relatives" to include spouses and unmarried minor children of U.S. citizens, and parents of adult U.S. citizens.
INA §201; 8 U.S.C. §1151.
"Parole," in immigration law, means that an alien has been granted temporary permission to be present in the United States. Parole does not constitute formal admission to the United States, and parolees are required to leave when the terms of their parole expire, or if otherwise eligible, to be admitted in a lawful status.
See U.S. Department of Homeland Security, Office of Immigration Statistics, Yearbook of Immigration Statistics, multiple years.
In this report, CRS presents immigration trend data over the last two decades, from FY1996 to FY2016.
Refugees are admitted to the United States from abroad while asylees are foreign nationals who request and receive asylum after having entered the United States. The number of refugees admitted each year is determined by the President in consultation with Congress. The number of asylees is not limited. For more information on refugee policy, see CRS Report RL31269, Refugee Admissions and Resettlement Policy, by Andorra Bruno. For background information on asylum policy, see CRS Report R41753, Asylum and "Credible Fear" Issues in U.S. Immigration Policy, by Ruth Ellen Wasem.
For a dependent foreign state, the per-country ceiling is 2%. For example, Macau, the former Portuguese colony that became a special administrative region of the Peoples' Republic of China in 1999, would be considered a dependent foreign state.
U.S. Department of State, Bureau of Consular Affairs, Operation of the Immigrant Numerical Control Process, undated, p. 3.
INA §202(a)(4); 8 U.S.C. §1152(a)(4).
INA §202(a)(5)(A); 8 U.S.C. §1152(a)(5)(A). This provision was enacted through the American Competitiveness in the Twenty-First Century Act of 2000 (P.L. 106-313).
For more information, see CRS Report R43145, U.S. Family-Based Immigration Policy, by William A. Kandel.
See CRS Report R44475, EB-5 Immigrant Investor Visa.
For background information, see CRS Report RL33977, Immigration of Foreign Workers: Labor Market Tests and Protections, by Ruth Ellen Wasem.
Employment-based allocations are further affected by the Nicaraguan and Central American Relief Act (NACARA, Title II of P.L. 105-100), as amended by §1(e) of P.L. 105-139. NACARA provides immigration benefits and relief from deportation to certain Nicaraguans, Cubans, Salvadorans, Guatemalans, nationals of former Soviet bloc countries, and their dependents who arrived in the United States seeking asylum. NACARA Section 203(e) states that when the cut-off date (the visa availability date for oversubscribed immigration categories) for the employment 3rd preference "other worker" (OW) category reaches the priority date (the filing date) of the latest OW petition approved prior to November 19, 1997, the 10,000 OW numbers available for a fiscal year are to be reduced by up to 5,000 annually beginning in the following fiscal year. Since the OW cut-off date reached November 19, 1997, during FY2001, the reduced OW limit began in FY2002 and will continue until all NACARA adjustments are offset. Also, employment-based allocations are affected by the Chinese Student Protection Act (P.L. 102-404), which requires that the annual limit for China be reduced by 1,000 until such accumulated allotment equals the number of aliens (roughly 54,000) acquiring immigration relief under the act. Consequently, each year, 300 immigrant visas are deducted from the 3rd preference category and 700 from the 5th preference category for China. See U.S. Department of State, Visa Office, Annual Numerical Limits for Fiscal Year 2018.
For more information, see CRS Report R45102, Diversity Immigrants' Regions and Countries of Origin: Fact Sheet, by Jill H. Wilson.
The INA provides 55,000 diversity immigrant visas each year. However, beginning in FY1999, that annual ceiling has been reduced by up to 5,000 each year to accommodate adjustments made under NACARA, similar to the reduction of the 3rd employment-based preference category. The 5,000 offset is temporary, but it is unclear for how many years it will remain in effect to handle these adjustments of status.
See CRS Report R43892, Alien Removals and Returns: Overview and Trends, by Audrey Singer.
U.S. Department of Homeland Security, Office of Immigration Statistics, FY2016 Yearbook of Immigration Statistics, Table 6. FY2016 represents the most recent data available on permanent immigration from DHS.
U.S. Department of Homeland Security, Office of Immigration Statistics, 2016 Yearbook of Immigration Statistics, Table 2.
U.S. Department of Homeland Security, Office of Immigration Statistics, 2016 Yearbook of Immigration Statistics, Table 7.
DOS's National Visa Center handles immigrant visa processing. U.S. Department of State, Annual Report of Immigrant Visa Applicants in the Family-Sponsored and Employment-Based Preferences Registered at the National Visa Center as of November 1, 2017.
The priority date is the date that an immigration petition—which DOS is currently processing for a numerically limited visa—was received by USCIS. Priority dates listed in the Visa Bulletin indicate that DOS is currently processing visas for petitions that were originally submitted to USCIS as of those dates. For further specifications of the data that DOS factors into the visa priority dates, see U.S. Department of State, Visa Office, Annual Numerical Limits for Fiscal Year 2018.
The relatively small proportion of employment-based petitions in the visa queue (3%) reflects the relatively more stringent criteria for employment-based LPR sponsorship compared with that for family-sponsored petitions, the relatively larger pool of potential sponsors for family-sponsored petitions, and employers' time-sensitivity to meeting their labor force requirements compared with family-sponsored petitioners who typically are able to wait for considerably longer periods to be reunited with family members.
Performance data from the first quarter of FY2018 indicate that 3.7 million LPR petitions were pending. See https://www.uscis.gov/tools/reports-studies/immigration-forms-data/data-set-all-uscis-application-and-petition-form-types.
For further discussion of numerical limits and backlogs for employment-based petitions, see CRS Report R42048, Numerical Limits on Permanent Employment-Based Immigration: Analysis of the Per-country Ceilings.
U.S. Department of State, Bureau of Consular Affairs, Visa Bulletin For March 2018, February 9, 2018.
For more on the family-sponsored visa queue, see CRS Report R43145, U.S. Family-Based Immigration Policy, by William A. Kandel.
Other aspects of the U.S. immigration system that also typically receive attention during calls for reform include increased border security and enforcement of immigration laws within the U.S. interior, reform of temporary worker visas, and options to address the millions of unauthorized aliens residing in the country.
As an example of this approach, in June 2013, the Senate in the 113th Congress passed S. 744, a comprehensive reform bill that would make significant changes to the system of permanent legal immigration. For a full discussion of S. 744 as passed, see CRS Report R43097, Comprehensive Immigration Reform in the 113th Congress: Major Provisions in Senate-Passed S. 744, by Ruth Ellen Wasem.
On February 15, 2018, the Senate voted on four immigration proposals, including S.Amdt. 1959 to H.R. 2579 introduced by Senator Charles Grassley. The amendment would have substantially reduced permanent immigration by limiting family-sponsored immigration to spouses and unmarried children (under age 18) of U.S. citizens and LPRs and by terminating the Diversity Immigrant Visa Lottery. The amendment, which also included provisions related to border security and the Deferred Action for Childhood Arrivals (DACA) population, was defeated by a vote of 39-60.

References: §203
 §1153
 §203
 §1153
 §204
 §1154
 §207
 §1157
 §208
 §1158
 §240
 §1229
 §1101
 §245
 §212
 §1182

§202
 §1152
 §201
 §201
 §1151
 §202
 §1152
 §202
 §1152
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