A panel of lawmakers was asked to look into how the state could transition to a flat tax rate. But they found that the state needs to address a $7 billion question mark first.
The report from the 2020 Tax Policy Study Commission claims a flat tax rate could be beneficial for the state.
But the commission also says a transition would be challenging because of its 120-plus tax expenditures.
The state foregoes $7 billion dollars in revenue a year from these so-called loopholes.
Republican leaders have said a flat tax would reduce taxes and simplify code.
Opponents argue that a flat tax would mean most Ohioans would pay more for a small portion to pay less.
A separate group is looking into how the state can reduce its expenditures, which liberal and conservative think tanks support.