Summary: GAO discussed the Immigration and Naturalization Service's (INS) implementation of its legalization program for undocumented aliens. GAO noted that INS: (1) opened 107 offices for application processing and 4 regional facilities to complete final processing; (2) contracted with a private data processing center to enter application data into its computer system; (3) charged application fees comparable to immigration entry fees; (4) permitted aliens to file applications with community organizations; and (5) contracted with an advertising agency and participated in public education activities to promote program awareness. GAO also noted that INS: (1) estimates that 1.3 to 1.5 million aliens would apply for legalization were less than initial forecasts of 2 to 3.9 million; (2) activities resulted in high program awareness among Hispanics, although some did not apply for fear of ineligibility; (3) application fees will cover program costs if INS does not extend its application deadline; (4) operational problems did not threaten the program's viability; and (5) program elements were somewhat similar to those in other countries. GAO believes that, since it has no reliable data to forecast the number of eligible aliens who have not applied or will apply to the program, it has no basis to challenge or support a deadline extension.