Montana's revenue chief says there's a possibility the state will have to call another special session of the Legislature to address a possible budget shortfall resulting from changes to federal tax law.

Department of Revenue Director Mike Kadas tells Montana Public Radio that without a special session, the state could face a $46 million hole in its budget under an initial reading of last year's changes to the tax code.

That's about 2 percent of Montana's annual general fund budget.

Kadas says that if the state changes it interpretation of the tax code changes, it could result in the agency blocking deductions called for under the new law. He says that would prompt lawsuits from taxpayers.