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Follow-Up Report On INS Efforts To Improve
The Control Of Nonimmigrant Overstays

Report No. I-2002-006
April 2002



In 1997, the Office of the Inspector General (OIG) issued an inspection report, Immigration and Naturalization Service Monitoring of Nonimmigrant Overstays (Report Number I-97-08), which assessed the Immigration and Naturalization Service's (INS) monitoring of nonimmigrant visitors who stay in the United States beyond the period of time permitted by their status at entry (overstays). The report also examined the INS's Nonimmigrant Information System (NIIS), its principal database for identifying overstays. In the report, we found that the INS often could not conclusively identify individual nonimmigrant overstays, that the INS could not adequately describe the characteristics of the overstay population in the United States, and that the INS did not have an enforcement strategy that effectively targeted overstays. Furthermore, we determined that NIIS was not producing reliable overstay data, either in the aggregate or for individual nonimmigrants.

The original OIG report made recommendations to improve the collection and analysis of available data on overstays, to improve the reliability of NIIS data, and to develop an effective enforcement strategy targeted at overstays. In the wake of the September 11 terrorist attacks, the OIG conducted several follow-up reviews of prior OIG reports to determine what progress the INS had made to address the recommendations in those reports. This follow-up review, which is the fifth in the series of follow-up reports, 1 evaluated the INS's progress in implementing the recommendations from our 1997 report on the INS's monitoring of nonimmigrant overstays.


The INS inspected over 35 million nonimmigrants at approximately 133 air ports of entry (POE), approximately 1 million at sea POEs, and an additional 195 million nonimmigrants at land POEs in fiscal year (FY) 2001. The INS regularly collects information to evaluate the effectiveness of its enforcement of immigration laws, including nonimmigrants' status at admission to the United States and the duration of their stay in this country.

NIIS is the INS's primary information system to track whether nonimmigrants have entered or left the United States. The INS Form I-94, Arrival/Departure Record, is the primary source of information entered into NIIS. Form I-94 is divided into two parts - an arrival portion that includes the nonimmigrant's name, date of birth, passport number, airline, flight number, country of citizenship, and address while in the United States, and a departure portion that includes the alien's name, date of birth, and country of citizenship. Each Form I-94 contains a unique admission number printed on both portions that the INS uses to record and match the arrival and departure records of nonimmigrants. The INS furnishes the Form I-94 to the airlines to give to nonimmigrants to complete. Upon arrival at a POE, the nonimmigrants present the form to immigration inspectors for review at the same time they present their passports or other travel documents. The immigration inspectors retain the arrival portions of the Form I-94 and the nonimmigrants retain the departure portions. The departure portions are supposed to be collected by representatives of the airlines and turned over to the INS upon the nonimmigrants' departure from the air POE. The INS forwards both the arrival and departure portions to contractors who enter the information from the forms into NIIS.

NIIS captures data on only about 15 percent of all nonimmigrant entries into the United States, primarily aliens entering through air and sea POEs and some aliens entering through land POEs. Canadians and Mexicans crossing at land POEs, who constitute 85 percent of nonimmigrant entries, are generally exempt from the Form I-94 requirements.

The INS estimates the current illegal alien population to be approximately 7 million. 2 The common perception that the vast majority of illegal aliens entered the United States by surreptitiously crossing the southwest or northern border is inaccurate. INS officials have testified before Congress that 40 to 50 percent of the illegal alien population entered the United States legally as temporary visitors but failed to depart when required. The INS commonly refers to these illegal aliens as nonimmigrant overstays, and according to the INS this population is growing by at least 125,000 a year.

In 1996, Section 110 of the Illegal Immigration Reform and Immigrant Responsibility Act (IIRIRA) directed the INS to develop an automated entry-exit tracking system that collects a record of departure for every alien and matches it with a record of the alien's arrival. The system also was required to have an on-line capability to identify nonimmigrant overstays and produce reports of the results of the matching by country. This overstay information was to be integrated into databases of the INS and the Department of State, including those used at POEs and at consular offices.

However, the Canadian government and some northern border members of Congress opposed the entry-exit system requirement on grounds that it would adversely affect the movement of goods and people across the northern border. In 1998, Congress amended Section 110 to state that the system should not significantly disrupt trade, tourism, or other legitimate cross-border traffic at land POEs. In June 2000, the Data Management Improvement Act (DMIA), Public Law 106-215, further amended Section 110 to bar the imposition of any new documentary or data collection requirements to satisfy the requirements of Section 110, including requirements on aliens for whom documentary requirements have been waived (i.e., Canadians), or requirements that are inconsistent with the North American Free Trade Agreement. The amended Section 110 set the following deadlines for development of the entry-exit system: December 31, 2003, for airport and seaport POEs; December 31, 2004, for the 50 high-traffic land border POEs; and December 31, 2005, for the remaining POEs.

After the terrorist attacks of September 11, 2001, the effectiveness of monitoring nonimmigrant visitors came under additional scrutiny, as authorities considered how to identify and locate terrorists who might be in the United States. The USA Patriot Act of 2001, enacted on October 26, 2001, requires that the integrated entry-exit control system be implemented with all deliberate speed and that the Attorney General, the Office of Homeland Security, and others immediately establish an Integrated Entry and Exit System Task Force to accomplish this task. The USA Patriot Act also mandates a focus on biometric technology and development of tamper-resistant documents that will be machine readable at POEs. Further, it requires that the system interface with law enforcement databases and provide access for federal law enforcement authorities so that they can identify and detain individuals who pose a threat to national security.

Scope and Methodology

For this follow-up report, we reviewed recent INS correspondence, conducted extensive research of legislation related to entry-exit alien control systems and the Visa Waiver Program (VWP), and reviewed Congressional Research Service reports and Congressional testimony. The INS Statistics Office provided the OIG with INS-wide inspection data from air, land, and sea POEs for FY 1999 through FY 2001. We also interviewed INS officials, including officials from the INS Inspections and Statistics offices and the Program Manager at the INS Lookout Unit, as well as Department of State personnel.


  1. The four reports already issued are "Follow-Up Report on the Visa Waiver Program (December 2001)," "Status of IDENT/IAFIS Integration (December 2001)," "Follow-Up Report on Improving the Security of the Transit Without Visa Program (December 2001)," and "Follow-Up Report on the Border Patrol's Efforts to Improve Security Along the Northern Border (February 2002)."

  2. Data from the 2000 Census suggests the number may be at least 8 million. Scholars at Boston's Northeastern University estimated the number as close to 13 million in a February 2001 study, An Analysis of the Preliminary 2000 Census Estimates of the Resident Population of the U.S. and Their Implications for Demographic, Immigration, and Labor Market Analysis and Policymaking.