Enacted in 2000, the American Competitiveness in the 21st Century Act (AC21) provides two important provisions by allowing foreign nationals to change jobs before obtaining a green card (visa portability), and to extend their H-1B visa status beyond the 6-year statutory limit. Prior to AC 21, H-1B foreign nationals had to depart the U.S. after they had been in H status for 6 years. If they had adjustment of status application filed, they would have to keep working for the same employer for years until they obtained their greencards. With AC21, foreign nationals now have much more flexibility to change jobs or extend their H-1B status until a decision is made on their Adjustment of Status application.