India, Sept. 12 -- The United States quietly implements a new immigration rule that reshapes the lives of thousands of immigrant families-especially those from India. The rule changes how the government calculates a child's age for green card eligibility. On paper, it looks like a minor technical adjustment. In practice, it means many children of long-term immigrants-particularly dependents of H-1B visa holders-'age out' of the process by turning 21 before their family's green card is approved. Once that happens, they lose their dependent status and are no longer in the immigration queue for citizenship.

At first, it may feel like just another bureaucratic step. But to students and parents planning higher education, it is much bigger-it ...