Currently, Medicaid covers children from low-income households and people with disabilities mostly.
The federal government is requiring states to expand coverage to include adults earning less than $15,000 a year.
Some estimates show the requirement will add 17 million people to Medicaid coverage over the next 10 years.
At issue: How will Arkansas be able to pay for it?
As it stands, Arkansas could see a shortfall between $250 million to $450 million before the new law goes into effect.
Lars Powell, a healthcare insurance expert at UALR, says so far no one has come up with any ideas.
The big challenge for lawmakers is coming up with a way to pay for Medicaid expansion that is palatable to taxpayers, he said.
A spokesman for Gov. Mike Beebe said Arkansas will likely start feeling the budget impact of the new Medicaid rule starting in 2017.