Many years of debate about unauthorized immigration to the United States culminated in the enactment of the Immigration Reform and Control Act (IRCA) of 1986. That year, there were an estimated 3.2 million unauthorized aliens in the country. IRCA coupled legalization programs for certain segments of the unauthorized population with provisions to deter future unauthorized immigration by reducing the magnet of employment. These latter provisions reflected a belief, widely held then and now, that most unauthorized aliens enter and remain in the United States in order to work. To reduce the job magnet, IRCA amended the Immigration and Nationality Act (INA) to add a new Section 274A, which makes it unlawful to knowingly hire, recruit, or refer for a fee, or continue to employ, an unauthorized alien, and requires all employers to examine documents presented by new hires to verify identity and work authorization and to complete and retain employment eligibility verification (I-9) forms. The IRCA provisions did not have the effect of curtailing future illegal immigration. After falling to an estimated 1.9 million in 1988 as eligible unauthorized aliens legalized their status, the unauthorized population began to grow. By the early 1990s, it had surpassed pre-IRCA levels. The I-9 process was effectively undermined by the ready availability of genuine-looking fraudulent documents. Ten years after the enactment of IRCA, Congress attempted to strengthen the employment verification process as part of the Illegal Immigration Reform and Immigrant Responsibility Act of 1996 (IIRIRA). IIRIRA directed the Attorney General to conduct three largely voluntary pilot programs for electronic employment eligibility confirmation. After examining documents and completing I-9 forms as required under INA Section 274A, employers participating in a pilot program would seek to confirm the identity and employment eligibility of their new hires. IIRIRA tasked the Attorney General with establishing a confirmation system to respond to inquiries made by participants in these pilot programs "at any time through a toll-free telephone line or other toll-free electronic media concerning an individual's identity and whether the individual is authorized to be employed." The former Immigration and Naturalization Service (INS) within the U.S. Department of Justice had initial responsibility for administering the employment eligibility confirmation pilot programs. In 2003, DHS assumed this responsibility. The Basic Pilot progra m, the first of the three IIRIRA employment verification pilots to be implemented and the only one still in operation, began in November 1997 in the five states with the largest unauthorized alien populations at the time. In December 2004, in accordance with P.L. 108-156 , the program became available nationwide, although it remained primarily voluntary. The Basic Pilot program has changed over the years. Since July 2005, it has been entirely internet-based. It is administered by DHS's U.S. Citizenship and Immigration Services (USCIS). The Basic Pilot Program was briefly renamed the Employment Eligibility Verification (EEV) Program by the Administration of George W. Bush, and was again renamed E-Verify by that Administration in August 2007. IIRIRA, as originally enacted, directed the Attorney General to terminate the Basic Pilot program four years after going into effect, unless Congress provided otherwise. Congress has extended the life of the Basic Pilot program/E-Verify multiple times. Most recently, it extended E-Verify until September 30, 2018, as part of the Consolidated Appropriations Act, 2018. As part of the I-9 process, all employers must review documents presented by new hires to verify their identity and employment authorization and, along with the new hires, must complete I-9 forms. Employers participating in E-Verify then must submit information from the I-9 form about their new hires (name, date of birth, Social Security number, immigration/citizenship status, and alien number, if applicable) via the internet for confirmation. The information in the employer's query is automatically compared with information in SSA's primary database, the Numerical Identification File (Numident), which contains records of individuals issued Social Security numbers. For those employees identifying themselves as citizens, if the information submitted by the employer matches the information in Numident and SSA records confirm citizenship, the employer is notified that the employee's work authorization is verified. If the information submitted by the employer about a self-identified citizen matches the information in Numident but SSA records cannot confirm citizenship, the information is automatically checked against USCIS naturalization databases. If this check confirms citizenship, the employer is notified that the employee's work authorization is verified. If the employer-submitted information about a new hire does not match information in Numident, the employer is notified that the employee has received an SSA tentative nonconfirmation finding. In cases in which the employer-submitted information matches SSA records but the individual self-identifies as a noncitizen, the information is sent electronically to USCIS for verification of work authorization. If the USCIS electronic check confirms work authorization, the employer is so notified. If the electronic check does not confirm work authorization, an Immigration Status Verifier (ISV) at USCIS checks additional databases. If the ISV is unable to confirm work authorization, the employer is notified that the employee has received a USCIS tentative nonconfirmation finding. Employers are required to notify their employees about SSA and USCIS tentative nonconfirmation findings. If an employee chooses to contest a tentative nonconfirmation finding, the employer must refer the case to SSA or USCIS, as appropriate. The employee has eight federal government work days from the referral date to contact the appropriate agency to resolve the issue. If an employee does not contest the finding within that period or the contest is unsuccessful, the system issues a final nonconfirmation. If an employee receives a final nonconfirmation finding that he or she believes is incorrect, the employee may contact USCIS to have the case reviewed. The E-Verify program continues to grow. On January 31, 2006, there were 5,272 employers enrolled in the program, representing 22,710 hiring sites. Six years later, on March 17, 2012, there were 345,467 employers enrolled, representing more than 1,090,000 hiring sites. On April 2, 2018, employer enrollment in E-Verify stood at 779,722, and there were more than 2.5 million participating sites. Based on the number of firms in the United States in 2015 according to U.S. Census Bureau data, these enrolled employers represented about 13% of U.S. employers. As the number of enrolled employers has grown, so has the number of employer queries, or cases, received by E-Verify. Between FY2007 and FY2017, the annual number of E-Verify queries increased more than tenfold, from about 3.3 million to about 34.9 million. For general comparison purposes, there were about 65.3 million nonfarm hires in the United States in calendar year 2017, according to the Bureau of Labor Statistics. As mentioned, E-Verify is a largely voluntary program. Under IIRIRA, however, violators of INA prohibitions on unlawful employment or those who engage in unfair immigration-related employment practices may be required to participate in a pilot program. IIRIRA also states that each department of the federal government and each Member of Congress, each officer of Congress, and the head of each legislative branch agency "shall elect to participate in a pilot program." In August 2007, the Office of Management and Budget (OMB) issued a memorandum requiring all federal departments and agencies to begin verifying their new hires through E-Verify as of October 1, 2007. In addition, federal regulations that went into effect in 2008 and 2009 included new E-Verify participation requirements, as discussed below. USCIS, which administers E-Verify, is a fee-supported agency. Until FY2007, funding for the Basic Pilot program came from unrelated USCIS fees. (As discussed below, employers are not charged a fee to participate in E-Verify.) In recent years, however, Congress has provided funds for E-Verify as part of DHS/USCIS appropriated funding for Research, Development, Training, and Services. Since FY2009, Congress has appropriated at least $100.0 million each year for E-Verify. For FY2018, the Consolidated Appropriations Act, 2018, includes $131.5 million for E-Verify. Although the unauthorized alien resident population has declined in size since its 2007 high point of an estimated 12 million, it remains substantial. According to a preliminary estimate by the Pew Research Center, unauthorized alien residents in the United States numbered about 11.3 million in 2016. The Pew Research Center has also estimated that there were some 8.0 million unauthorized workers in the civilian labor force in 2014. Policymakers have considered an expansion of electronic employment verification—whether though E-Verify or a new system—as a key option for addressing unauthorized employment. Electronic employment eligibility verification measures have been introduced in recent Congresses. Among these measures are bills that have variously proposed to make E-Verify permanent, make E-Verify mandatory for all employers or a subset of employers, permit or require the verification of previously hired workers through E-Verify, and authorize a new electronic employment eligibility verification system. Although no broad measures along these lines have been enacted, some more limited provisions have been enacted, including language to extend the E-Verify program (see " E-Verify "). Some bills with major electronic employment eligibility verification provisions, however, have seen legislative action in recent years. In the 113 th Congress, the Senate passed a comprehensive immigration reform bill, the Border Security, Economic Opportunity, and Immigration Modernization Act ( S. 744 ), that included such provisions.