A FAIRLY MUTED Health Policy Commission on Tuesday unanimously accepted a first-of-its kind cost containment plan put forward by Mass General Brigham, ending a nine-month process to rein in spending by the state’s largest health care system.

Commissioners seemed relieved at Mass General Brigham’s willingness to come up with nearly $128 million in annual savings as part of an untested process that is largely voluntary. Mass General Brigham could have boycotted the process by paying a $500,000 fine, but commission officials said that possibility was never broached.

The hospital system in May initially proposed $70 million in savings, but after consulting with Health Policy Commission staff decided to increase that number by nearly $58 million.

Even with the higher number, commission officials warned that it won’t be enough to change the upward trajectory of health care spending in Massachusetts.

Marylou Sudders, the state’s secretary of health and human services, struck what was a common theme among the commissioners. “This is a tool, not the tool in what has to be a broader conversation,” she said.

“This is not going to solve our problems,” added David Cutler, a Harvard economics professor who serves on the commission. “I think it’s a step in a good direction.”

Deb Devaux, the new chair of the commission, said the agency is glad a deal was reached with Mass General Brigham but now must move on to monitoring and verifying that the savings targets are actually reached. “Our tone was not of celebration at this moment,” she said.

Anne Klibanski, the president and CEO of Mass General Brigham, issued a statement suggesting meeting the spending reduction targets won’t be easy.

“The pandemic has profoundly changed our lives, our economy, and it has permanently changed health care,” she said. “Hospitals and healthcare systems across the state, including Mass General Brigham, continue to operate over capacity, seeing more patients than they have beds for. Patients are sicker from delayed care, and we have no choice but to care for people in the hallways of our emergency departments. Combined with labor and supply chain shortages, this can make it difficult to provide the right care, at the right time. Despite the challenges we encounter in our work, we remain committed to transforming how care is delivered and lowering the cost of that care, while improving quality of life for our patients.”

The commission paired its discussion of the Mass General Brigham cost-containment plan with approval of its annual cost trends report, which outlined a series of troubling trends that are threatening to undermine efforts to keep health care spending from exceeding a state benchmark.

Commercial health care spending, for example, rose faster in 2020 than the national average for the first time since 2013. Drug spending is rising rapidly, with the average out-of-pocket for a 30-day supply of prescriptions for chronic diseases such as diabetes and arthritis rising 50 percent between 2017 and 2020..

According to the codes used by hospitals to assess the severity of inpatient illnesses, patients are coming in sicker. In 2013, 28.1 percent of patients were in the two most severe categories; by 2020, that percentage had risen to 41.1 percent. Health Policy Commission officials suspect hospitals are using the codes to inflate their pricing.

The cost trends report tracked what it would cost each hospital in the state to supply a market basket of 50 common outpatient services in 2020 and found a $26,000 difference between the most expensive and least expensive facilities.

The five most expensive hospitals include three on the Cape and islands and Boston Children’s Hospital and the Dana Farber Cancer Institute. The sixth and seventh slots were occupied by Massachusetts General and Brigham and Women’s, the flagship hospitals of the Mass General Brigham system.

David Seltz, the executive director of the Health Policy Commission, said the agency needs new tools to address the alarming cost trends, including “escalating financial penalties” for health care providers that exceed benchmarks.

He also appealed to the Legislature on behalf of the commission for the power to set caps on hospital prices, limit hospital facility fees, expand state oversight of the entire pharmaceutical sector, and limit increases in health insurance premiums.

Commissioner John Kryder, a primary care physician, said the health care sector needs to shift its business model away from getting paid for services provided.

“Volume-based care is driving everything up,” he said. “It’s going to get worse and we’re not dealing with a stable situation right now.”

Devaux agreed that the way the commission has operated over the last 10 years probably needs to change. “I do think it’s time to consider new approaches,” he said.