BOSTON - Mass General Brigham, the largest health care system in Massachusetts, announced layoffs Monday that will affect hundreds of workers, citing a $250 million projected budget gap.

The layoffs could potentially impact employees at 12 hospitals under the MGB umbrella: While executives say the sweeping cuts are aimed at management and administrative-level employees with no impact on front-line workers, Boston University School of Public Health’s David Rosenbloom suspects the changes could reach patients.

Facing rising costs and hoping to make its sprawling network more efficient, the state’s largest private employer aims to cut payroll costs by over $200 million.