A subtle change with major implications is coming to the H-1B visa program that could give large tech companies an edge in bringing highly skilled workers to their sprawling Silicon Valley campuses, while hurting outsourcing firms that hire entry-level workers to fill software jobs. The Department of Homeland Security announced a rule change Wednesday that will transform the lottery that decides who gets the 85,000 H-1B visas granted to for-profit companies every year.

The H-1B visa program has brought hundreds of thousands of foreign tech workers to the U.S. to work on everything from cutting-edge R and D to enterprise IT office support. A shift in the rules will change how many companies manage their hiring.