Under the Immigration and Nationality Act (INA), as amended, both the Immigration and Naturalization Service (INS) and the foreign and domestic international airline industry are charged with certain responsibilities for preventing the entry of passengers who are not legally entitled to admission to the United States. INS has ultimate responsibility for stopping all inadmissible passengers from entry. The airlines are responsible for preventing a subset of all inadmissible passengers (i.e., improperly documented passengers) from boarding flights bound for the United States.1 Our inspection focused on the interactions between INS and the airline industry.