Here are some questions and answers on why it matters and what the decision will mean to Ohio.
Q: What is Medicaid and who's covered by it?
A: The joint state-federal program helps pay for health care primarily for low-income children, pregnant women, disabled people and some parents. One of every five Ohioans — 2.3 million people — is on Medicaid.
Q: Why is the state considering expanding the program?
A: One of the key parts of President Barack Obama's federal health care overhaul is making Medicaid more widely available so that most Americans have access to health care. But last year the Supreme Court gave states the right to reject the Medicaid expansion.
Q: How many people will be able to get Medicaid if the state eases the eligibility requirements?
A: Nearly a half-million uninsured Ohioans would get coverage by 2022, one study estimated. The majority will be lower-income adults who don't have children.
Q: How is that determined?
A: Eligibility is based on how much money you make. People who make up to 138 percent of the federal poverty line — about $15,400 for an individual or just over $26,300 for a family of three — could be covered by an expanded Medicaid program.
Q: How does this affect everyone else?
A: Supporters say reducing the number of people without insurance will cut down on the costs passed on to those with health insurance and hospitals that treat the uninsured when they're ill. Opponents argue the federal government already is spending too much and this will add more to the debt.
Q: So who would pay for a Medicaid expansion?
A: The federal government will pick up the full price for the first three years and 90 percent over time.
Q: But how much would this cost the state?
A: It depends who you ask. One study said Ohio could make $1.4 billion over the next decade because the state would see an increase in sales and health insurance tax revenues. It predicted the savings would eventually drop and just about break even.
Q: If there's the potential for no cost to Ohio, why is there debate over doing this?
A: The biggest concern is that the federal deficit will continue to grow and that politicians in Washington will eventually shift the Medicaid costs to the states. That would be a huge expense, given that about 20 percent of Ohio's spending already goes toward Medicaid.
Q: So does the governor have the final say on expanding Medicaid?
A: No, the state's House and Senate must sign off on the plan too if Kasich wants to broaden the program in 2014.