Mississippi lawmakers return to the Capitol at 10 a.m. Thursday for a special session designed to keep Medicaid alive and funded.

Much is at stake: Medicaid is a government health insurance program for the needy, and it covers about 644,000 of the state’s nearly 3 million residents. It’s a big source of money for nursing homes, hospitals, pharmacists and other health care providers.

Under the federal health law signed by President Barack Obama in 2010, states have the option to expand Medicaid. Because of partisan bickering over whether to add another 300,000 people to the program in Mississippi, lawmakers ended their three-month regular session without authorizing the program to exist beyond this coming Sunday, the end of the budget year. With that deadline approaching, lawmakers find themselves under increasing pressure to act.

Few are willing to predict how long they’ll be in Jackson — it could be one day, or they could work through the weekend. A special session costs $43,451 per day for lawmakers’ salaries and expenses. For one round trip to the Capitol, legislative expenses add $20,159 to the cost.

Democrats are in the minority in the House and Senate, and they pushed for Medicaid expansion during the regular session. Now, they’re talking about a different way to cover the uninsured. Instead of adding the 300,000 newly eligible people to Medicaid starting next January, Democrats propose letting the people in that group use government subsidies to purchase health insurance on the private market.

“We’re hopeful that we’ll have an opportunity to get a vote and have a discussion,” House Democratic leader Bobby Moak of Bogue Chitto said Wednesday.

Republican leaders, including Gov. Phil Bryant, say Mississippi can’t afford Medicaid expansion, even with the federal government paying most of the tab. Bryant has said Democrats’ latest proposal is simply a repackaging of expansion.

Only a governor can call a special session, and he tells lawmakers what topics they can consider. Bryant’s declaration for the session does not include renewal of an existing hospital tax that helps pay for Medicaid or renewal of a part of state law that delineates Medicaid services. Without the tax, it would be difficult — maybe even impossible — for lawmakers to set a balanced budget for the program.

Bryant spokeswoman Nicole Roberts said Wednesday that lawmakers’ first priorities should be reauthorizing the program and approving a spending plan. She said she doesn’t know if the governor will bring the hospital tax up for consideration.

“If he needs to expand it, he has the authority,” Roberts said of the session’s agenda.

Renewing the tax takes a 60 percent majority, while reauthorizing Medicaid and setting a spending plan require only a simple majority.

Under the federal law, states can extend Medicaid coverage to people earning up to 138 percent of the federal poverty level, or about $15,000 a year. The cutoff in Mississippi now is about $5,500 a year, but Medicaid still does not cover many able-bodied adults at or below that income level.

The federal government would pay 100 percent of medical expenses for the newly qualified enrollees from 2014 to 2017. The federal share would be reduced to 90 percent by 2020, with each state paying the balance.  Bryant has said he doesn’t trust Congress to fulfill its funding promises and he doesn’t want state government to be left with large obligations it can’t afford.