A study of the effects of expanding Medicaid eligibility in Pennsylvania finds it would net serious federal funds without blowing a hole in the state budget.

But the Corbett administration is still urging caution on the issue.

A report by the state's Independent Fiscal Office finds that opting into a Medicaid expansion would bring billions of federal dollars into the state, and mean millions of dollars in savings for the commonwealth.

But baked into the study are several assumptions necessary for completing a fiscal analysis, said IFO director Matthew Knittel.

"From the administration's standpoint, they can't do that, they have to wait and see for a definitive ruling from the feds," he said Tuesday.

A Corbett administration official says the total costs and savings that may come from an expansion still hinge on things federal government hasn't decided yet.

One example: Will the state be able to continue to levy a tax under the expansion that would yield millions of dollars in additional state revenue?

Knittel says the IFO study assumes the tax will stay in place. What, he says, if that assumption is wrong?

"Not a game changer, though it is significant," he said.

The Corbett administration's concern is that all the other significant assumptions might be wrong -- and add up to one big game changer.

The IFO study was requested by the Senate Democrats, who have repeatedly called on the governor to accept the Medicaid expansion to increase health-care access and for its potential to bring federal funding and jobs to the state.