As the U.S. Senate voted to open debate on the Republican plan to repeal the Affordable Care Act, state lawmakers began their own review of potentially significant changes to Massachusetts' health insurance for the poor. In the interests of balancing the budget an insuring the viability of state health aid, Gov. Charlie Baker is making a big push to rein in Medicaid spending. The result: some Democrats are offering more vocal opposition than Beacon Hill is used to hearing – at least since Baker moved into the corner office. 

The cost of MassHealth, the state's Medicaid program, has ballooned by almost 50 percent over the last 10 years. Baker's plan would transfer around 140 thousand non-disabled adults from MassHealth to their employer's plan or to subsidized coverage through the Health Connector. Health and Human Services Secretary Marylou Sudders says there would be little change to coverage and premiums, but co-pays could rise to around $500 a year. 

"I've read some things recently that suggested that we're actually cutting people off of access to eligibility. Nothing could be farther from the truth in our proposals before you," Sudders told a joint hearing before the Legislature's budget and health care financing committees Tuesday.

Because the cost of MassHealth is growing much faster than state tax dollars, Baker's finance officials insist eligibility must be paired back to preserve the program for the neediest residents and to maintain the state's near-universal coverage rate.

"In 2006, we passed universal health care reform, providing the path to the [Affordable Care Act] and today we need to find the path to preserve and protect our gains in coverage," Sudders said.

Over one quarter of Massachusetts residents, almost 2 million people, rely on MassHealth for at least some health care coverage, according to Sudders. Baker's plan would affect MassHealth enrollees earning 130 percent or less of the federal poverty line, or about $16,000 a year.

According to Baker's office, the changes to the program would save the state around $200 million a year.

Democrats on the panels are concerned that forcing people off MassHealth and onto the connector would mean the loss of some dental and long-term care coverage, as well as push the state away from its long-standing commitment to expanding access to health insurance.

Ashland Sen. Karen Spilka, the Senate's top budget writer, said there need to be solutions to the cost problem that don't include limiting local Medicaid enrollment, which was expanded under the Affordable Care Act.

"If we accepted the governor's proposal on this, Massachusetts would be the first state in the nation to start rolling back Medicaid expansion. That is not a direction I would like to see Massachusetts going. We are a Commonwealth. We take care of our residents, particularly our most vulnerable residents," Spilka told WGBH News.

Several progressive members of the House echoed Spilka's position in an op-ed for CommonWealth Magazine earlier this week. Reps. Christine Barber, Ruth Balser and Jay Livingstone called Baker out for what they see as supporting policies at the local level that he's condemned the national GOP for pursuing nationwide.

"These are exactly the types of cuts that the governor is publicly opposing in Washington," the representatives wrote.

Baker insists the changes are needed to balance this year's budget and keep MassHealth sustainable.

The MassHealth eligibility changes are paired with another proposal from Baker to increase how much employers pay into the system and to charge an assessment on companies that don't provide affordable coverage to employees.