WASHINGTON — The governor of Indiana, Mike Pence, on Thursday proposed using federal Medicaid funds available under the Affordable Care Act to expand a state health insurance program to cover an additional 350,000 low-income adults. But unlike traditional Medicaid, the plan would require many participants to make monthly contributions toward the cost of coverage.

Under the law, if states expand Medicaid to cover adults with incomes up to 138 percent of the poverty level, the federal government will pay the full cost through 2016. The poverty level is $11,670 for an individual. Mr. Pence is among several Republican governors who have opposed expanding traditional Medicaid, calling it a failure, yet have pursued the federal money for alternative models.

The program he wants to expand, the Healthy Indiana Plan, uses a mix of state and federal money to cover about 45,000 residents who live below the poverty line but do not qualify for traditional Medicaid. It requires them to contribute about 2 percent of their income toward their first $1,100 worth of care.

Mr. Pence’s plan, which needs federal approval, would allow all nondisabled adults with incomes up to 138 percent of the poverty level to receive coverage through Healthy Indiana starting next year. But all would have to make monthly contributions toward the first $2,500 of their care, or, if they choose a more basic level of coverage without dental or vision benefits, pay small co-payments for drugs and medical care. The monthly contributions would range from $3 to $25, depending on income.