Summary

Each year, millions of visitors, foreign students, and immigrants come to the United States. Visitors may enter on a legal temporary basis--that is, with an authorized period of admission that expires on a specific date--either (1) with temporary visas (generally for tourism,business,or work) or, in some cases (2) as tourists or business visitors who are allowed to enter without visas. (The latter group includes Canadians and qualified visitors from 27 countries who enter under the visa waiver program.) The majority of visitors who are tracked depart on time, but others overstay. Four of the 9/11 hijackers who entered the United States with legal visas overstayed their authorized periods of admission. This has heightened attention to issues such as (1) the extent of overstaying, (2) weaknesses in our current overstay tracking system, and (3) how the tracking system weaknesses and the level of overstaying might affect domestic security.

Significant numbers of foreign visitors overstay their authorized periods of admission. The Department of Homeland Security estimates the resident overstay population at 2.3 million as of January 2000. Because the starting point for this estimate is the 2000 census, it does not cover short-term overstays who have not established residence here. It also omits an unknown number of potential long-term overstays from Mexico and Canada. Because of unresolved weaknesses in DHS's current system for tracking arrivals and departures (e.g.,noncollection of some departure forms and inability to match other departure forms to arrivals), there is no accurate list of overstays. Two new tracking initiatives are intended to address these weaknesses. NSEERS, the National Security Entry and Exit Registration System, does not cover most visitors. US-VISIT, the U.S. Visitor and Immigrant Status Indicator Technology, a more comprehensive,automated program, is being phased in. While its design and implementation face a number of challenges, evaluating US-VISIT against the weaknesses GAO identifies here would increase its potential for success. The current tracking system's weaknesses limit control options and make it difficult to monitor potential terrorists who enter the country legally. Like other illegal immigrants, overstays obtain jobs with fraudulent identity documents, including jobs at critical infrastructure locations, such as airports. Thus, tracking issues can affect domestic security and are one component of a layered national defense. Improving the tracking system could work with intelligence, investigation, information-sharing, and other factors to help counter threats from foreign terrorists.