In what could be a tumultuous year for state and local finances, these five issues are likely to take center stage.

Many Capitol Hill watchers expect federal tax reform to roll forward in some fashion in 2017 now that a Republican will be in the White House. There are two major proposals on the table that could directly result in higher costs for states.

For starters, many in Congress have been supportive of limiting the tax-exempt status of municipal bonds. Removing this tax perk for bond investors would force governments to offer higher interest rates on the debt, thus increasing their cost of paying off that debt.

It’s hard to overstate the potential impact of such a move. One estimate pegged the current tax perk savings for state and local governments at about $714 billion from 2000 to 2014. For its part, the federal government estimates it loses as much as $30 billion in potential income tax revenue each year as a result of the perk.