AUGUSTA, Maine — Dozens of people packed a hearing room Tuesday to testify on a bill that would sign Maine up for an expansion of its Medicaid program under the federal Affordable Care Act, a move that could provide about 55,000 additional residents with health insurance coverage.

Lawmakers on the Legislature’s Health and Human Services Committee heard testimony from health care providers, residents who would potentially gain coverage, law enforcement officials, activists and others as they considered the bill, LD 1066, which is sponsored by Rep. Linda Sanborn, D-Gorham.

Most testified in support of the bill, with some making pleas to cover Maine residents who would be newly eligible for coverage and others arguing it makes fiscal sense for the state to accept additional federal funding to expand Medicaid.

“The federal government has set aside money to expand MaineCare for people exactly like us,” said Patricia Kidder, a Sanford resident who, along with her husband, lost Medicaid coverage when their youngest daughter turned 18. They’re now on a waiting list for a different category of Medicaid services, she said. “Low-income adult individuals, ages 22 through 64, need you to accept the federal funds and expand MaineCare. We need it to stay alive.”

Those who spoke against the expansion cautioned lawmakers on the Legislature’s Health and Human Services Committee against banking on a promise for funds from the federal government at a time when the federal government is facing a massive debt and is trying to trim deficits.

“I do have deep concerns with the fiscal situation of our federal government,” said Joel Allumbaugh, who runs an insurance brokerage firm and heads up health reform initiatives at the right-leaning Maine Heritage Policy Center. “We’ve never had broken promises, but we’ve never been in the fiscal crisis we’re in today, either.”

The hearing on Sanborn’s bill came as Gov. Paul LePage, who has long opposed expanding Medicaid, discusses a potential expansion with federal officials. Maine Health and Human Services Commissioner Mary Mayhew last month requested that the federal government cover 100 percent of Maine’s expansion costs for a decade — rather than the three years prescribed in federal law — as a condition for Maine to participate in the expansion.

Rep. Ken Fredette of Newport, the House Republican leader, encouraged Health and Human Services Committee members to author a bipartisan bill and to coordinate its efforts with those of the LePage administration.

“If this committee comes out with something with less than unanimous support, it will be tough sledding for this particular bill,” said Fredette, who testified neither for nor against the expansion bill. “The chief executive has a role to play in this.”

Under the federal health care law, if states choose to expand their Medicaid programs, the federal government will cover 100 percent of costs for newly eligible Medicaid recipients for three years. The 100 percent funding will gradually drop to 90 percent in 2020 and states will have to make up the remaining share.

Maine, however, expanded its Medicaid program about a decade ago to many of the people who would otherwise be eligible for the first time under the Affordable Care Act. That means fewer residents in Maine would qualify for 100 percent federal funding. But the federal government is promising to increase its share of costs for states such as Maine that have already expanded Medicaid.

That means the state would receive more federal funds to provide Medicaid coverage for some people — mostly adults without children — it’s already covering.

A recent Kaiser Family Foundation analysis projects that Maine would be one of 10 states to see the amount of state funds it spends on Medicaid actually drop over the next decade — by $570 million, or 3.8 percent — while the federal share of Medicaid expenses would rise by $3.1 billion, or 11.4 percent.

The Kaiser analysis also projects Maine’s hospitals would see $348 million more in payments from Medicaid over the next decade if the state expanded the program. Hospitals also would have to provide less care for which they aren’t paid, according to the analysis.

But Mayhew, Maine’s health and human services commissioner, told lawmakers that Maine will, overall, be penalized by the federal government for having expanded Medicaid coverage before the Affordable Care Act passed in 2010. That’s because the federal government wouldn’t cover 100 percent of expansion costs in Maine during the first three years while it’s covering 100 percent of similar costs for similar populations in other states.

Under the expansion arrangement in federal law, Mayhew said, Maine would end up spending more in state funds in coming years to insure parents already covered by the state’s Medicaid program and approximately 50,000 adults without children who would gain coverage.

Plus, Mayhew said, the expanded program would require 93 new staff members to administer, costing the state another $7 million annually.