Summary: In response to a congressional request, GAO assessed future trends in legal immigration based on S. 358, which changed the effective date of proposed immigration legislation to fiscal year (FY) 1991. GAO found that the bill proposed three major changes to legal immigration by: (1) changing the system for allocating family-preference visas by basing available visas on the level of immediate-relative immigration, rather than having the current limitation of 216,000 family-preference visas; (2) providing more visas to unmarried adult children and spouses of U.S. resident aliens and fewer visas to brothers and sisters of adult U.S. citizens; and (3) creating a new class of selected immigrants who would qualify under a point system on the basis of criteria such as their education, English language ability, and occupation. GAO also found that: (1) the total number of immigrants during the 10-year period would remain about the same; (2) immediate-relative immigration would remain the same until 1996, when aliens would receive their citizenship and could petition for their immediate relatives' entrance; (3) further increases would occur when selected immigrants became citizens and petitioned for their families' entrance; (4) projections reversed the current pattern, in which the 8 high-demand countries had more family-preference immigration than the 167 remaining countries; (5) the volume of labor-market-based immigration would double to about 120,000 annually until FY 1993, then increase to about 150,000 thereafter; and (6) visa waiting list pressures would have the most impact on visas to unmarried adult children and brothers and sisters of resident aliens.