North Carolina Gov. Roy Cooper (D) is following through on his plan to make health care accessible to uninsured people by expanding Medicaid coverage through the Affordable Care Act (ACA).

Cooper’s office said in a statement Friday that he had sought approval from the Centers for Medicare & Medicaid Services (CMS) to expand Medicaid in the Tar Heel state. Cooper’s administration said it would file a state amendment plan to CMS this month after accepting public comment on the move to offer health care to half a million people.

Cooper’s announcement comes just days after he said he would make sweeping health-care changes under the ACA, the News & Observer reported. Meanwhile, Congressional Republicans are working to repeal the ACA, which could leave 20 million people without access to health care and cost up to 3 million jobs, according to a report from the Milken Institute School of Public Health at George Washington University.

In Arkansas and Kentucky, two states that expanded Medicaid, people with low incomes reported better access to health care than people with low incomes in Texas, according to a JAMA Internal Medicine article published in August 2016. Researchers found that Medicaid expansion reduced the uninsured rate in 2015 by 22.7 percentage points in Kentucky and Arkansas.

Cooper’s CMS notice comes less than a month after the state’s Republican-majority General Assembly passed controversial legislation that legal experts said was designed to eviscerate the Democratic governor’s powers.

More than 500,000 North Carolinians could receive new health-care benefits next January, under several conditions: CMS must approve Cooper’s request, and North Carolina must both secure local matching money in the joint federal-state program and change the state’s eligibility requirements, the governor’s office said.

According to Cooper, the state could receive upwards of $4 billion in Medicaid funds to pay for health care. “That will create jobs, bolster our hospitals, could save some rural hospitals and work toward more stable private insurance premiums,” Cooper said in a statement.

Some lawmakers, including Republican state Senate Leader Phil Berger, have called the governor’s plans unconstitutional. Cooper, however, said on Friday that a 2013 state law prohibiting the governor from seeking health-care coverage for North Carolinians with low incomes does not apply to his plans.

Cooper argued in a statement that North Carolina should join Washington, D.C., and the 31 states that have enacted Medicaid expansion under the ACA. He added that North Carolina tax dollars already pay for health care for people with low incomes in other states, but not for the state’s own people.

Cooper in his inaugural address on Saturday reiterated his stance on Medicaid expansion. “It’s long past time to expand Medicaid, so more working North Carolinians can get the health care they need. It just makes common sense,” he said.