Tens of thousands of people would lose their health care coverage and the state's administrative costs would increase if a proposal to change Montana's Medicaid expansion program becomes law, a study released Wednesday said.

The draft of a bill sponsored by Republican Rep. Ed Buttrey called for adding work requirements, increasing premiums and making other changes to the program that enrolls about 95,000 low-income adults.

A study of those changes was commissioned by the nonpartisan Montana Healthcare Foundation and conducted by the Center for Health Policy Research at George Washington University based in part on the effects of work requirements in Arkansas and Kentucky.

The analysis estimates between 31,000 and 43,000 Montanans would lose Medicaid expansion coverage due to work requirements and premium increases, with the bulk being due to the work and associated reporting requirements.

The state's administrative costs would rise due to tracking whether enrollees are meeting work requirements or have an exemption.

"Given the lack of evidence that work requirements improve employment or income and the abundant evidence that they cause low-income people to lose benefits, the evidence indicates that Medicaid work requirements create more harm than good," the report concluded.