CHARLESTON, W.Va. -- States will face risks no matter which side of the Medicaid expansion debate they decide on, the director of a state governments agency said Sunday.

And state lawmakers -- not just governors -- will have a say in whether or not to expand Medicaid coverage under the Affordable Care Act, Chris Whatley, director of the Council of State Governments, told the Southern Legislative Conference. The conference is meeting in Charleston this week.

While the news media have largely focused on whether state governors favor the expansion, expanding Medicaid will ultimately require legislative action, Whatley said.

The Affordable Care Act requires states to expand Medicaid to people with incomes up to 133 percent of the federal poverty level. However, the U.S. Supreme Court ruled that the federal government cannot take away all of a state's Medicaid funding if states refuse to expand coverage.

In West Virginia, Gov. Earl Ray Tomblin has not publicly stated his preference on whether or not to expand coverage. He recently sent a letter to the U.S. Department of Health and Human Services seeking more information on the matter.

The cost of expanding differs depending on whom you ask and what you take into account, Whatley said.

"There's been a ton of different numbers that have been developed over the last two years as to what the true state cost is," he said.

An initial estimate was $20 billion over 10 years, he said. That estimate took into account a cost of $6,000 per patient and only considered the expansion population, he said.

But one cost factor besides the expansion population is the people who are eligible for Medicaid now who will come into the program due to the individual mandate and the publicity surrounding health-care reform, he said.

Whatley said the people who are eligible for Medicaid and have not yet come into the program represent the biggest cost to states under the Affordable Care Act.

Whatley cautioned the lawmakers to be sure they know what is being taken into account when estimates are given about the cost.

"You've got to pick your numbers and you've got to unpack whatever number your governor gives you to figure out if they are dynamically scoring other things other than the expansion population," he said.

Another factor to consider is that the federal government could provide incentives to expansion.

"They have tremendous ability to make your life easier in other ways to incentivize you, not to coerce but to incentivize you to expand Medicaid," he said.

Whatley said some states have been hesitant to develop their insurance exchanges because the public is divided on the issue of the Affordable Care Act. But there are risks to not implementing an insurance exchange as well. If a state does not implement an exchange, the federal government will put in place an exchange that benefits the federal bottom line, Whatley said.

Reach Lori Kersey at lori.ker...@wvgazette.com or 304-348-1240.