A new report claims Gov. Jan Brewer’s decision to expand Medicaid, using funds from the Affordable Care Act, will sharply increase the number of people in the program.

About 1.3 million Arizonans are currently enrolled, and that’s with substantial eligibility limits. The new law boosts eligibility to 138 percent of the poverty level, up from the current 100 percent.

Michael Bond, of the free market group the National Center for Policy Analysis, says that will add about 1.1 million in the first year, a figure disputed by both the governor’s office and Matthew Benson, representing Arizona hospitals that support expansion.

“The report doesn't say how they get to that figure,” Benson said. “Right? It doesn't say. They're seemingly pulling a lot of these figures out of the air.”

But Bond, a finance lecturer at the University of Arizona, says with federal advertising about fines for those who don’t have coverage, the figures could be higher,

“Remember: You've got this marketing campaign going on with these exchanges, and a lot of people going in thinking they're going to buy health insurance are all of a sudden being put into Medicaid,” Bond said.

The Medicaid expansion faces its first legal test in court on Friday.