The aim of this study was two-fold: firstly, it attempted to focus on the earnings of foreign-born STEM professionals in the U.S. workforce to examine whether this population was at an earning disadvantage compared to the U.S. citizens. Secondly, it aimed to investigate whether legal status acquisition (from temporary work visas to permanent residency) enhanced the earnings of foreign-born STEM professionals in the U.S. workforce. This study utilized a mixed-methods (QUAN/QUAL) research design. ANCOVA (Analysis of Covariance) was used to test the hypothesis in order to determine any statistically significant differences between the group means. Secondary data from the National Survey of College Graduates (NSCG) was utilized for this study. The results of the ANCOVA test showed that temporary worker visa holders were not at earning advantage/disadvantage compared to the U.S. citizens, and there was no statistical evidence that legal status acquisition enhanced the salaries of the foreign-born STEM professionals in the U.S. workforce. The interviews indicated that foreign-born STEM professionals (temporary worker visa holders, LPRs, and naturalized U.S. citizens) were not at earning disadvantage compared to their U.S.-born counterparts. Although the legal status change did not enhance the salaries of the skilled immigrants, it did improve job mobility and overall flexibility.