The Associated Press

BOSTON — The state Department of Public Health has ordered Massachusetts hospitals to stop turning away ambulances when their emergency rooms are overcrowded.

By Jan. 1, hospitals must discontinue their "diversion'' closures because the decades-old practice has interfered with patient choice, increased time patients spend in ambulances, tied up vehicles and shifted crowding to other hospitals.

But the change will be a challenge for hospitals, especially Massachusetts General Hospital in Boston, which relies on temporary emergency room closures. The hospital is working to prepare for the change by focusing on ways to discharge patients from the hospital earlier in the day, freeing up beds for patients waiting in the emergency room.