The House passed the Medicaid expansion before they left for summer break, but the Senate put off the vote two months ago.
It's a heated issue that could need a tie-breaker.
The showdown in the republican-dominated chamber could determine whether hundreds of thousands of state residents will qualify for government-provided health care starting in January
Medicaid already covers 1.9 million Michigan residents, mainly low-income children, pregnant women and the disabled.
The debate is whether to cover nearly a half-million more adults making up to 133-percent of the poverty level.
Our sources tell us it will likely come down to a tie breaker, with Lieutenant Governor Brian Calley casting the deciding vote.
We're told Senate Republican Majority Leader Randy Richardville has personally called all of his senate colleagues regarding the vote.
Governor Snyder has been urging lawmakers to vote for the expansion for months.
"I don't view this as a partisan issue, I don't make decisions through a partisan lens," said Governor Snyder. "I've made tough decisions that people on both ends of the political spectrum have not necessarily liked. I wasn't hired to make everyone happy. I was hired to do right and best for Michiganders and this is clearly the right thing to do."
We'll be bringing you live team coverage from Lansing throughout the day. Newschannel 3's Andy Dominianni and Political Reporter David Bailey will both be at the state capitol covering the Medicaid showdown from every angle.
You can look for live reports starting at noon.