Herbert's comments come a day after Republicans on a House committee replaced an anti-health reform bill with a bill prohibiting the governor or health department from expanding Medicaid.
The governor is fretting the short- and long-term costs of expanding Medicaid to cover 131,000 Utahns under 138 percent of the federal poverty line, both for the state and federal government.
He also voiced concern about leaving some without affordable health coverage options.
And he added he's open to innovative alternatives, such as a partial expansion pitched by fellow Republican, Gov. Scott Walker of Wisconsin. Utah's analysis should be ready in time to make a decision this summer, he said.
The federal health law defers to governors as the deciders on the expansion. Should HB391 pass the House and Senate, it would put Herbert in the position of signing legislation nullifying his authority.
He declined Thursday say if he'd veto the bill, saying, "Let's see if it gets to my office."
Utah Democrats issued a statement blasting Republicans for ignoring the economic and public health benefits of covering the state's uninsured.
"Either they're looking for political cover to allow them to refuse the expansion in yet another metaphorical middle finger to President Obama, or they have badly lost control of their own caucus," said Utah Democratic Party executive director Matt Lyon. "If we refuse the expansion, we will be on the hook for the hospital bills that the uninsured can't pay, and money that Utahns paid [in federal] taxes will go to cover the Medicaid expansion in other states that did opt in, like New Jersey and Arizona."
Some Republicans on the House committee that pushed the bill through expressed similar concerns.
But the measure won support from surprising corners, garnering a yes vote from Rep. Jim Dunnigan, R-Taylorsville, chairman of the Legislature's Health Reform Task Force.
Consumer advocates aren't convinced a Wisconsin-style compromise would work for Utah, but they'd like the opportunity for an informed debate. Wisconsin struck a middle ground with its proposal to extend Medicaid coverage to adults living under the poverty line while moving some above that income level into subsidized private insurance via Obamacare's online exchanges.
HB391 would tie Utah's hands, giving it no leverage to negotiate local solutions with the feds, said Matt Slonaker, Medicaid Policy and Collaborations Director at the Utah Health Policy Project.
Republican governors in other states, including New Jersey and Florida, have embraced the Medicaid expansion. If Utah passes, it will mean forgoing federal funding. The federal government has committed to foot the entire cost of the expansion in the first years, phasing down to 90 percent.
Wisconsin will, instead, get its regular federal match rate of 60 percent for its newly eligible adults.