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.

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.

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.