Study says GOP plan would be blow to Mass.

President Trump addressed the news media on May 4 after the House passed a GOP-backed health care proposal.Mark Wilson/Getty Images

Massachusetts, the state with the highest rate of residents with health insurance, could see its uninsured rate jump above 10 percent if the sweeping health care bill approved by the US House becomes law, according to a new analysis.

The bill known as the American Health Care Act, which is backed by House Republicans and President Trump, would repeal huge portions of former president Obama’s health care law. It would slash billions of dollars from Medicaid and other programs that subsidize health care for lower-income Americans.

A report from the Washington-based Urban Institute roughly confirmed some of the estimates previously released by Governor Charlie Baker’s office and local health care advocacy groups. It said the House bill would cut $1.4 billion in federal Medicaid funding for Massachusetts by 2022. To maintain coverage in the Medicaid program, known as MassHealth, the state would need to find funding on its own or make major changes to the program.

Without additional funding, about 355,000 adults on MassHealth could be dropped from the program. Another 90,000 who buy subsidized plans on the Health Connector, a state insurance exchange, also are likely to lose coverage because their subsidies would be rolled back, making the plans too expensive, the report said.

In all, 445,000 people could lose coverage, pushing Massachusetts’ uninsurance rate up to 10.3 percent. That would be a setback for a state that passed its own law mandating universal health coverage more than a decade ago, before the passage of the Affordable Care Act, or Obamacare. Fewer than 3 percent of the state’s residents lack health insurance, according to the Census Bureau.

“If [the House bill] comes to pass, it would put Massachusetts back to a rate of uninsured worse than what we were prior to all the work that we’ve done on health care reform in the Commonwealth,” said Audrey Shelto, president of the Blue Cross Blue Shield of Massachusetts Foundation. “The gains that we’ve achieved . . . would be more than erased.”

The foundation commissioned the study on behalf of a local coalition that opposes repeal of the Affordable Care Act. That coalition includes dozens of groups representing hospitals, doctors, employers, labor unions, and others.

The governor, a Republican, opposes his party’s attempts in Washington to blow up the current law. He sent a letter to US senators last week, warning that the House bill poses a “significant threat” to Massachusetts.

Baker’s spokeswoman, Lizzy Guyton, said in a statement that the administration is reviewing the new Urban Institute report. The administration “has repeatedly raised concerns over any changes to the health care law that would result in massive funding cuts for the Commonwealth and negatively impact our ability to deliver world-class health care coverage to individuals and families,” she said.

Senators have said that they will develop their own health care bill, which could be very different from the House version. Both the House and the Senate need to agree on legislation before it can pass.