Medicaid expansion may not have replaced all of the lost subsidies, but it would have helped, hospital administrators said.

“I understand that the state needs to balance its budget, and control the runaway costs of Medicaid, but to turn a blind eye and say, ‘Let the chips fall where they may,’ you’ll end up with a gutted health care system,” said Maggie M. Gill, chief executive at Memorial Health.

Traditionally, safety-net hospitals have played a special role in caring for poor people. They make up just 2 percent of acute care hospitals in the country, but provide about a fifth of all uncompensated care, according to Dr. Arthur Kellerman, dean of the F. Edward Hébert School of Medicine in Bethesda, Md. The subsidy was created in the 1980s to help hospitals with large shares of patients who were uninsured or had government insurance that did not pay very much. Many hospitals came to depend on it.

A full third of Grady’s patients have no insurance, and, if that does not change, the hospital will have no choice but to cut services, said John M. Haupert, Grady’s chief executive. The hospital’s large outpatient mental health program, which handles 58,000 visits a year and is critical to keeping poor patients with behavioral problems from seeking treatment in the emergency room, would most likely be hit, Mr. Haupert said.

Some experts say the cuts in hospital subsidies are part of a larger problem: government programs like Medicaid do not pay enough to cover the actual costs of care. The cheapest private insurance on the new health care exchanges, the Bronze Plan, covers just 60 percent of costs, leaving low-income people who buy it with a lot of out-of-pocket costs that hospitals worry the patients will not be able to pay.

A spokeswoman for the Centers for Medicaid and Medicare Services said that some of the reductions in the subsidy should not hurt safety-net hospitals because states have discretion over how the money is distributed and should be focusing on hospitals with the most uncompensated care. And while there is no special exception for states that did not expand Medicaid, federal officials have said they will revisit that in 2016.

But experts and hospital administrators said it was unlikely that the federal government would make adjustments that would reward states that refused to expand Medicaid. And the health care landscape is changing so rapidly, they say, that the subsidies are crucial to keep going over the next few years.