WASHINGTON — The Department of Veterans Affairs, legally designated as the backup health care system in national emergencies, is preparing to absorb the overflow of coronavirus patients from private hospitals if — or when — they become strained to the breaking point. It would be the biggest test the sprawling and sometimes troubled government hospital system has faced.

The department is experienced in managing an older and vulnerable population, and in many ways, it could be better prepared than the rest of the health care system to take on the task. It has a surplus of beds in many of its 172 hospital centers and a robust number of special rooms for patients with breathing disorders. Leaders at the agency say they have a surplus of supplies that they have been ordering since the beginning of the year.

“Nobody has asked for our help at this point, but the American people should know we are ready,” said Dr. Richard A. Stone, who is in charge of the Veterans Health Administration.

But several current and former officials said they feared that in this case, the department would be hampered by its highly centralized and often opaque management culture, which has left some critical players unsure of how the department is preparing and what is expected of its tens of thousands of employees.