The first detailed analysis of what the American Health Care Act would look like in Massachusetts is out.

"It paints a devastating picture," Brian Rosman, policy director at Health Care for All, said of the Republican bill championed by Speaker Paul Ryan and President Trump that was passed by the House earlier this month.

For more than a decade, Massachusetts has had the lowest number of residents without health insurance in the nation. The rate dropped after the passage of a 2006 state coverage law and has remained low under Obamacare. But a study from the Urban Institute, a D.C.-based think tank that bills itself as independent, projects the state's uninsured rate would rise from 2.8 percent to 10.3 percent by 2022 — a nearly fourfold increase.

"We would actually go back to worse coverage than we had pre-Romneycare, pre-2006," Rosman said. The uninsured rate was 8.6 percent in 2005.

That’s the worst of two scenarios the study outlines. Under that worst case option, 445,000 residents would lose all or some health coverage. Most of those people — 355,000 — are currently covered under an expansion of Medicaid included in Obamacare. The remaining 90,000 would be expected to lose or drop coverage when the subsidies they receive are no longer available.

In the second scenario, the state spends $1.1 billion to fund the Medicaid expansion but assistance with insurance costs ends — so those 90,000 people still drop their coverage.

"It looks to me like a lose-lose scenario," Rosman said. "Either way people in Massachusetts would have worse health care and more expensive taxes due to the loss of federal funding."

The study was commissioned by the Blue Cross Blue Shield of Massachusetts Foundation for a coalition of more than 70 groups formed to assess the state’s options if Obamacare is repealed. Several members of the coalition say the challenges spelled out by the report are daunting.

"It’s going to take a tremendous revival of the commitment we all had as a community back in the early 2000s to come together, to figure out how to retain the maximum level of coverage we can in the face of this type of legislation," said Audrey Shelto, president of the Blue Cross Blue Shield of Massachusetts Foundation.

But Shelto says there's a commitment in the state to making sure residents have health insurance. "We're fortunate to be in a state where almost all of the major stakeholders are really, really committed to retaining coverage and have worked very hard to get us to where we are today," Shelto said.

The Urban Institute analysis aligns with projections from Gov. Charlie Baker's administration. He outlined concerns in a letter to House leaders and has turned his attention to the Senate as they draft their own Obamacare replacement plan.

"We have always maintained that coverage is very important as a health care sort of bottom line in our state," said Marylou Sudders, Baker's secretary for health and human services. "We have the highest rate of coverage in the country, we need to preserve that. But we also need to make sure that Medicaid is sustainable in the long run."

The state’s largest employer group is among those who expect a more moderate bill to come out of the Senate.

"While there is serious concern about the numbers in this study, I think that’s moderated a bit by the belief that this is not the bill that's going to end up coming out of the Congress" said Chris Geehern, executive vice president at Associated Industries of Massachusetts.

Geehern says the report shows the state and country have to figure out how to spend less money on health care.

"This underscores, again, the crying need for everyone to kind of roll up their sleeves and start working on health care costs," Geehern said.

Some experts question the findings of the Urban Institute report.

"It is odd that there is not a broader discussion of the impact of tax credits for those currently not eligible for them under the ACA, for example, those making over 400 percent of the federal poverty level," said Josh Archambault, senior fellow on health care policy at the Pioneer Institute.

And Archambault says a change in regulations could mean more residents move from public to private insurance plans. The report estimates 38,000 people would make this move, part of the reason employer costs would increase by $296 million a year as of 2022.

Uncertainty about what’s ahead from Capitol Hill is making a lot of providers, insurers, policy wonks and patients in Massachusetts anxious.

Laura Kiesel, a freelance writer and editor in Arlington, is counting on Medicaid in the coming months for diagnostic tests. She has some early signs of multiple sclerosis. Kiesel says she isn’t sure what she would do without Medicaid, known in this state as MassHealth.

"If I have these extra costs of health care, I don’t know how I’d be able to afford to live in the Boston area, I don’t know how I’d be able to afford to live at all," Kiesel said.

The report says health care spending for all households would rise about $253 million a year with higher deductibles and co-pays.