THEY GOT THE band back together.

Twenty years after Massachusetts passed landmark health care reform legislation that gave the state the highest rate of insurance coverage in the country, the leading players behind the law gathered in the same storied meeting hall where the 2006 bill was signed to celebrate their uncommon achievement.

Legislators greeted the activists who pushed them to act. Business leaders and health care administrators who worked out disagreements sat shoulder to shoulder in the audience. And underscoring what a singular feat it all was, five Massachusetts governors came together, as Gov. Maura Healey was joined by four of her predecessors, two Democrats and two Republicans, at Monday’s event at Faneuil Hall in Boston.

Against the backdrop of the dysfunctional, toxic climate that now defines Washington, the health care bill’s embrace by the state’s overwhelmingly Democratic Legislature and the Republican governor who signed it into law seems even more remarkable today.

The common cause that united them, not any differences they had, animated the bipartisan bonhomie that marked Monday’s commemoration.

“Political rivals respected each other, buried political weapons, and worked together to find solutions,” former governor Mitt Romney said from the same stage where he signed the law 20 years ago. “The political leaders who were part of this effort came to the job to get things done, not just to see what we could do to get ourselves reelected.”

The celebration came as the state faces tremendous threats to its effort to maintain near-universal coverage, and with business leaders, health care officials, and state leaders conceding that they have done little to tame runaway health care costs. The state has the highest average cost for employer-based family premiums in the country, the state Health Policy Commission reported last fall.

The crowd gave a warm welcome to Romney, who said that after his recent six years in Washington as a US senator from Utah, “I have greater appreciation for what we did here in Massachusetts.” There was no talk about serving as governor here making him feel like “a cattle rancher at a vegetarian convention,” a line he used in southern states when trying to buff up his conservative credentials in the run-up to his 2008 presidential run.

Meanwhile, Sal DiMasi, the wise-cracking Massachusetts House leader during the health care reform, who once famously quipped that he “got frostbite” from a hug the more buttoned-down Romney gave him, began a long list of tributes with high praise for the former governor.

“First and foremost, I’d like to thank Gov. Mitt Romney,” said the 80-year-old DiMasi, who has weathered life-threatening cancer as well as five years in federal prison on corruption charges. “Governor, you showed the nation what could be accomplished when you work productively and respectfully.”

Former governor Deval Patrick, who was charged with overseeing implementation of the law when he took office in 2007, echoed the theme, saying Massachusetts officials showed what “collaborating across all kinds of difference and all sorts of interests can achieve in service of the common good.”

“It was never about perfection, never about ideological or partisan purity,” Patrick said. “Never about having to agree on everything before we worked together on anything.”

The 2006 law introduced generous new subsidies to help offset insurance costs for lower-income residents, required nearly all adults to obtain coverage, and set up a new insurance exchange, the Massachusetts Health Connector, where residents could shop for plans. It also imposed a fee on employers who did not meet a state standard for insurance coverage of their employees.

The law helped drive the rate of health care coverage in Massachusetts to the highest in the country – close to 98 percent – and served as the model for the Affordable Care Act signed by President Obama four years later, in 2010.

“You proved what’s possible when we look past partisanship and instead set our eyes on the common good,” said Gov. Maura Healey in her tribute to leaders of the 2006 effort. “You proved that government can do great things.”

As big an achievement as the 2006 law represents, its quest to expand access to health coverage was not accompanied by strategies to control health care costs. That’s now an overriding challenge facing the health system.

“Today in Massachusetts and across the country, we face a cost crisis,” said Healey. “Our nation’s health care system is broken. And Washington’s not going to fix it, certainly not anytime soon.” Tackling it, she said, is “a revolution, I think, we need to lead again, right here for Massachusetts.”

That has proven to be much easier said than done.

Deferring reforms aimed at controlling costs was a deliberate choice in crafting the access law 20 years ago, said Andrew Dreyfus, a former Blue Cross Blue Shield CEO, in a panel discussion that was part of Monday’s program. “We made an explicit decision to postpone discussion of cost and affordability,” he said of the reform law. The problem two decades later? “We really haven’t tackled that issue yet,” he said.

As difficult as it was to reach agreement on the 2006 law, it ultimately meant pumping more money into health care, something providers, insurers, and pharmaceutical companies are glad to see happen.

The math and the political equation are much harder when the talk turns to controlling costs, which are squeezing employers and individuals who are on the hook for higher premiums.

“It’s a harder nut to crack,” said Sarah Iselin, the current Blue Cross Blue Shield CEO. “You’re talking about someone’s revenue –— constraining someone’s revenue or taking someone’s revenue away.”

Rick Lord, the former CEO of Associated Industries of Massachusetts, said in a separate panel discussion during Monday’s program that an employer recently told him their annual health care premiums are set to increase by 24 percent.

“That’s not sustainable,” said Lord.

The Health Care Policy Commission reported in November that the average cost of family coverage in the state, including out-of-pocket expenses, exceeded $32,000 in 2024.

On top of the cost crisis, the state is facing a huge cut in Medicaid funding as a result of the federal reconciliation bill passed by Congress and signed last year by President Trump. It could result in 326,000 residents losing coverage and ultimately cost the state as much as $3.5 billion in federal funding once fully implemented.

Tom Dehner, a former state Medicaid director, said that between the sweeping Medicaid cuts and targeted reduction in coverage for immigrants being imposed, the state’s vaunted coverage achievement from the 2006 law will be under “very direct threat.”

Perhaps the clearest sign of the difficult road Massachusetts faces in reining in costs and contending with federal cuts came when MIT economist Jonathan Gruber, a key architect of the state law, was asked during the panel discussion how we should approach today’s challenges.

Gruber, who used sophisticated models and hard numbers to help shape the 2006 law, offered instead the kind of faith-based message that came from some of the clergy who spoke at the anniversary celebration. “Be relentlessly optimistic,” he said. “This law is a testament to the power of positive thinking.”