For several years, some Members of Congress have favored "comprehensive immigration reform" (CIR), a label that commonly refers to omnibus legislation that includes increased border security and immigration enforcement, expanded employment eligibility verification, revision of nonimmigrant visas and legal permanent immigration, and legalization for some unauthorized aliens residing in the country. Other Members of Congress may favor addressing these issues sequentially (e.g., by implementing enforcement provisions and perhaps reforming legal immigration prior to legalization), and/or may disagree with the legalization and increased legal immigration provisions that have been features of major CIR bills. Still others may be interested in legislating on some elements of CIR but not others. Leaders in both chambers have identified immigration as a legislative priority in the 113 th Congress. While the House Committee on the Judiciary has ordered reported several distinct pieces of legislation that aim to reform immigration law thus far in the 113 th Congress, the debate in the Senate has focused on a single CIR bill: the Border Security, Economic Opportunity, and Immigration Modernization Act ( S. 744 ). As introduced on April 16, 2013, S. 744 was the product of months of negotiations among four Democratic and four Republican Senators—the bill's original co-sponsors—a group widely described as the "Gang of 8." The Senate Judiciary held three days of hearings on S. 744 in April 2013 and then marked up the bill over five days in May, favorably ordering the bill reported by a vote of 13-5 on May 21, 2013. The Senate Judiciary Committee filed its written report on S. 744 on June 7. The Senate passed the motion to invoke cloture on S. 744 on June 11, 2013, by a yea-nay vote of 82-15. The full Senate debated S. 744 for several weeks in June and considered about two dozen amendments on the floor. Some amendments were folded into other amendments, the most significant of these being the Hoeven-Corker-Leahy amendment on border security ( S.Amdt. 1183 ), which the Senate approved by a yea-nay vote of 69-29. On June 27, 2013, the Senate passed S. 744 , as amended, by a yea-nay vote of 68-32. This report summarizes major provisions of S. 744 , as reported by the Senate Judiciary Committee and as modified and passed on the Senate floor. CRS's analysis focuses on eight major policy areas that encompass the U.S. immigration debate: comprehensive reform "triggers" and funding; border security; interior enforcement; employment eligibility verification and worksite enforcement; legalization of unauthorized aliens; immigrant visas; nonimmigrant visas; and humanitarian provisions. Some Members of Congress have raised concerns about proposals for comprehensive immigration reform on the grounds that the "bargain" some people see at the heart of such reform—tougher enforcement on the one hand and legalization plus visa reforms on the other—may be difficult to enforce. Some argue, for example, that while supporters of the 1986 Immigration Reform and Control Act (IRCA) promised that a one-time legalization, increased border enforcement, and a prohibition against employing unauthorized workers would solve the problem of illegal migration; some of IRCA's immigration enforcement provisions were incompletely implemented. Partly to allay these concerns, the first sections of S. 744 would make implementation of certain enforcement provisions pre-conditions for the bill's legalization provisions; and S. 744 would directly appropriate funding for certain enforcement measures. These "trigger" and funding provisions were subject to substantive changes on the Senate floor. As reported by the Senate Judiciary Committee, Section 3 of S. 744 would establish two sets of triggers for the bill's legalization and adjustment of status provisions. First , the Department of Homeland Security (DHS) may only commence processing applications for registered provisional immigrant (RPI) status (see " Registered Provisional Immigrants (RPIs) ") after DHS notifies Congress that the department has begun to implement a new Comprehensive Southern Border Security Strategy (Comprehensive Security Strategy) and Southern Border Fencing Strategy (Fencing Strategy) mandated by §5 of S. 744 (see "Border Security Strategies and Metrics"). DHS would be required to begin implementing the Comprehensive Security Strategy within 180 days after the bill's enactment. Based on the interplay between the triggers in §3 and other provisions of the bill, it appears that aliens likely could begin applying for RPI status within a year of the bill's enactment. Second , as reported by the Senate Judiciary Committee, §3 generally provided that DHS could not begin adjusting the status of persons from RPI to legal permanent resident (LPR) until certain "triggers" are met. Specifically, the DHS Secretary would have been required to certify that four benchmarks have been reached: (1) the Comprehensive Southern Border Security Strategy has been submitted and is "substantially deployed and substantially operational"; (2) the Southern Border Fencing Strategy has been submitted and implemented and is "substantially completed"; (3) DHS has implemented a mandatory employment verification system to be used by all employers (see "Interior Enforcement"); and (4) an electronic exit system to collect machine readable data is being used at air and sea ports of entry (see " Entry-Exit System "). The bill as reported also described an exception to these trigger provisions. If 10 years have elapsed since the bill's enactment and these benchmarks have not been met due to litigation, a Supreme Court ruling that implementation is unconstitutional, or a "force majeure," the Secretary shall permit RPIs to apply for LPR status. It is not clear, however, whether allowing such applications under this condition means that DHS would be permitted to adjust applicants to LPR status, or whether the previous sub-paragraph would prevent DHS from completing such adjustments until the benchmarks are met. These triggers would not have appl ied to adjustment of status for certain aliens who entered the United States as children (i.e., DREAMers) under Section 2103 of the bill or for aliens granted agricultural "blue card" status under Section 2201 of the bill. The timeline for these groups to adjust status is described in those two sections (see " DREAM Act " and " Agricultural Worker Legalization "). The Hoeven-Corker-Leahy Amendment modified the second set of S. 744 trigger provisions (i.e., the triggers for DHS to begin adjusting the status of persons from RPI to LPR status). The amendment would continue to exempt DREAMers and aliens granted blue cards; and it would not change language concerning the exception to the trigger requirement due to litigation, a Supreme Court ruling, or force majeure. But the amendment generally would augment and expand the main trigger requirements for DHS to begin adjusting RPIs to LPR status. In particular, DHS could not begin such adjustments until six months after the DHS Secretary, after consultation with the Attorney General, the Secretary of Defense, the Inspector General of DHS, and the Comptroller General of the United States, certifies to Congress and the President the following: The Comprehensive Southern Border Security Strategy includes certain elements added by the Hoeven-Corker-Leahy Amendment, and the Strategy is deployed and operational (see "Border Security Strategies and Metrics"). For purposes of the trigger provision, "operational" is defined to mean that the technology, infrastructure, and personnel deemed necessary by the Secretary (including specific technology allocations described in the bill, as modified) have been procured, funded, and generally are in current use by the Department to achieve effective control of the Southern border. The Southern Border Fencing Strategy has been submitted to Congress and implemented (see "Border Security Strategies and Metrics"). The Secretary must certify, pursuant to such Strategy, that at least 700 miles of pedestrian fencing are in place along the Southern border, including the replacement of existing vehicle barriers on non-tribal land with pedestrian fencing where possible, as well as the subsequent installation of secondary fencing in locations where the Secretary deems it necessary or appropriate. DHS has implemented a mandatory employment verification system to be used by all employers as required by Section 3101, (see "Electronic Eligibility Verification System"). DHS is using the electronic exit system created by Section 3303 at all international air and sea ports within the United States where Customs and Border Protection (CBP) officers are deployed. No fewer than 38,405 trained full-time active duty U.S. Border Patrol agents are deployed, stationed, and maintained along the Southern border. Section 6 of S. 744 would establish a Comprehensive Immigration Reform (CIR) Trust Fund and a CIR Startup Account. As reported by the Senate Judiciary Committee, the bill would have authorized the transfer of an initial $8.3 billion from the Treasury's general fund to the CIR Trust Fund, and $3 billion from the general fund to the CIR Startup Account. The Hoeven-Corker-Leahy Amendment modified the bill to increase the increase the initial transfer into the CIR Trust Fund to $46.3 billion, and authorized additional expenditures out of the fund.